There is a wide variety of open lecture materials that you can adapt to your own needs. Start your search on the following websites:

• edusources – A Dutch repository for a large variety of educational resources and expert communities. Material can be in Dutch or English.  
• OER Commons – A public digital library of OER with a large variety of topics, levels and types of resources.
• Merlot – OER repository that emphasises quality through peer-review and community contributions.
• Wikiwijs – Repository for primary to higher education. Website and materials are mainly in Dutch. 

Open textbooks are study books published with an open licence to reuse, revise and remix. They are available online free of charge. You can search for Open Textbooks on the following sites:

• Pressbooks – Repository specifically for books. Filter the licences to exclude “all rights reserved”. Books may include H5P learning activities.
• LibreTexts – A large repository that easily allows adaptation and integration of interactive elements in the books.
• Merlot textbooks – A large OER repository that emphasises quality through peer-review and community contributions.
• OER Commons – A public digital library of OER with a large variety of topics, levels and types of resources. Filter for Material type > textbook.
• edusources textbooks – A Dutch repository for a large variety of educational resources and expert communities. Material can be in Dutch or English.
• TU Delft OPEN Books – A small repository of open textbooks on technical topics.  

Open courses are a mix or collection of open teaching materials. You can find complete online open courses on the following sites:

• Merlot - A large OER repository that emphasises quality through peer-review and community contributions. Filter by Material Type > Online Course.
• OER Commons – A public digital library of OER with a large variety of topics, levels and types of resources.  Filter for Material Type > full course.
• MIT Open courseware – Open platform to access courses, lecture notes, exams, and videos from MIT.
• Class Central – Repository specifically for courses, with a large variety of topics.
• edusources – A Dutch repository for a large variety of educational resources and expert communities. Material can be in Dutch or English. Search in Community’s, or search in ‘Zoek leermateriaal’ > Zoeken > select voor Bruikbaar als > Cursus.

Wageningen University and Research has two internal image collections you can use for your publications and course materials:

• WUR Image Collections – Collections of images from WUR education or research activities. Some of the collections are under a Creative Commons license and can be re-used in educational settings. For each collection, you will find copyright information and how to obtain permission if necessary.  

External sites that provide images with an open licence (royalty-free) include:

• Wikimedia Commons Database
• Freerange Stock
• Pixabay
• StockSnap
• Pexels

These sites can be freely accessed. Some sites require that you make an account before using them.

To search the internet for open images, you can use Google Images Advanced Search and select “Creative Commons licences” under the “Usage rights” section.

Notes:

• We recommend that you do not use pictures in which people are recognisable to avoid issues with privacy and portrait rights.
• Platforms offering free-to-use images do not check if the images are indeed free to use. We advise you to do a quick check with Google reverse image search to ensure that the image is free to use.

• Search Creative Commons – a portal that provides access to search engines for a wide range of CC licenced media types. It allows searching sites like YouTube with a filter for Creative Commons licenced videos.
• Wikimedia Commons – a searchable database where you can find videos that are either explicitly freely licensed or that are in the public domain.

When you use scientific articles in open 'off-campus' courses, other users may be unable to access subscription-based scientific publications. Open Access and Free Access articles provide a legal way to use peer-reviewed papers in your teaching materials and courses. Most of them have a Creative Commons licence. You can find open or free access articles on the following sites:

• Directory of Open Access Journals
• Paperity
• ScienceOpen
• BASE OA search engine – harvests open documents from more than 4000 repositories.
• Google Scholar> all versions > among these versions, you may find an open one.

Alternative tip: replace the http://doi.org/ with http://oadoi.org or http://doai.io/ to find an open access version, if available.

• Mason OER metafinder is a search engine that can discover OER across multiple repositories. 
• Search Creative Commons is a portal that provides access to search engines for a wide range of different media types, such as music, 3D models and videos. The portal is set to search for CC licenced materials in the selected sources.
• Printables is a database of user-submitted models that are suitable for 3D printing. The files can be filtered by a specific licence.

When using the repositories in the “Finding open materials” section above, you can use the following criteria to select materials:

• Quality – is the material accurate? Does it contribute to conveying your message? Is it peer-reviewed? Does it cover the subject
• Recency – are the text and images up to date?
• Relevance – is the material attractive for your audience (including images)? Does the level of the material match your audience?
• Accessibility – is the material accessible to your audience? On which platform or format is it published? Think about language, use of images (alternative text) and accessibility for colour blindness.
• Licence – how do you want to use the material? How is the material licenced, and does it allow your intended use?

Open Educational Resources can have various licence types that affect how you can use them and what you are permitted to do with them. It is essential to check the licence of the material before you begin working with it. If you have any questions about specific copyright licences, you can contact the Copyright Information Point.

One of the most common licences found on Open Educational Resources, and the licence WUR recommends for OER that we produce, is the Creative Commons (CC) licence. Six different types of CC licences subsequently allow or restrict aspects of usage. Before usage, please check the conditions of the CC licenced material.

For more information about using Creative Commons licences, you can refer to the Copyright Information Point’s article on Ownership & Licences.

Open Educational Resources that use licences like CC permit you to do the 5R activities.

• You can retain the content, that is you can store it and make copies of it.
• You can reuse the content differently (for example, in a class, in a video, on a website).
• You can revise, adapt, adjust, modify or alter the content itself (for example, translate the content to another language, simplify or complexify information, etc.)
• You can remix the content with other materials to create something new (for example, incorporate chapters from different textbooks to make your own customised textbook). (Note: unless the work you are reusing is under a CC BY-ND or CC BY-NC-ND licence, then no derivatives are permitted)
• You can redistribute the original, revised, or remixed content with others, for example, distributing copies of the work to your students. You can choose the licence under which you are sharing the work again, unless the original work was under a CC BY-SA or CC BY-NC-SA. In this case, you can still share it, but you must reuse the exact same licence as the original.

When you reuse materials from others, you must correctly attribute the work to the creator, as we did in the section above. Other examples of Creative Commons attribution can be found here. When attributing, include at least:

• Title of the work.
• Author/creator. You are required to state the name of the person who owns the copyright. Mention both the original author and anyone who adapted the work if applicable, and refer to the version you use.
• Licence. You are required to state which licence applies to this work, with a link to the CC licence deed. If the original author included disclaimers on copyright (e.g. "Except where otherwise noted, this work is licenced via CC BY 4.0"), you should include this as well to inform other (re)users. 
• Source. State where the work can be found, preferably by sharing the original URL or DOI.

You can now use the adapted material in your teaching. In addition, you can share this material for others to use and adapt under an appropriate licence.

If you need help with licences and copyright, or are unsure how you can (re)use material, contact the Copyright Information Point.

1. Inspiration: you can be an example for others to learn from and inspire them to innovate with new methods or ideas.
2. Quality: sharing invites feedback that is useful for continual professional development.
3. Equity of opportunity in education: giving back to society through sharing own materials freely, to reach teachers and students beyond WUR. 
4. Accessibility: help teachers get access to materials that they can reuse, so they don’t have to reinvent the wheel. Make education more accessible to students who cannot afford textbooks or other expensive educational materials. 
5. Diversity & Inclusion: Collaboration with a broader group of educators and also co-creating with students enriches content through the diversity of perspectives and ideas; it also gives students the possibility to make educational content more relevant to their needs. 

You can share anything, such as images, videos, infographics, assignments, assessments, rubrics and complete courses. You can share original material made by yourself, or revised and remixed material. When developing your own material, create it to be open by design. You can share the material if:

• The material is of high quality. This should be the same level of quality as the materials you use for teaching.
• The material can be of value for other teachers and/or students.
• The material can be used in different contexts, ideally, thus being standalone.

Clear any copyright issues!

When you release your work either with a CC licence or in the public
domain, you have to ensure your work is free of copyright. Specifically check any images for copyright issues and CC licence!

When you use anything made by others, make sure the licence allows modifications (with a CC BY, CC BY-SA, CC BY-NC, or CC BY-NC-SA licence) or sharing under a different licence (with a CC BY, CC BY-ND, CC BY-NC, or CC BY-NC-ND licence).

Wageningen University and Research is transitioning from Library for Learning to edusources as the standard platform for finding and sharing WUR Open Educational Resources. You can learn how to use SURFsharekit to upload materials to edusources here.

• Choose a licence. When you want to share your teaching material openly, we recommend you licence your work with a Creative Commons licences. In this way, your work is not only freely available, but others also know what they may do with the material. Note that a CC licence cannot be revoked.

As stated in the Open Educational Resources Policy, the default licence for sharing WUR materials is CC BY-NC. This licence permits the reuse, modification and adaptation of your work, except for commercial purposes.

• Apply your licence. There is no need to register a licence. You can simply and clearly state a notice with a link to the deed. For example:

(Title of the work) © 2025 by Wageningen University & Research is licenced under CC BY-NC 4.0.

• Add a frontpage to the material with a description of the context of the material, key information, e.g. author(s), organisation, contact details, licence and version.
• Add metadata to increase the discoverability of the material. Metadata is the “behind the scenes” data explaining the information in the OER. A repository can organise and categorise the materials based on metadata. Therefore, it is added to the repository (e.g., SURF ShareKit) by the creator or administrator. Metadata can include the title, author, CC licence, subject, education level, type of material, language, format, keywords, and more.