Acknowledgements

This free course was written by Ray Ison, Mike Walker and Miguel Valdez and was first published in December 2025.

OpenLearn editor: Dale Harry

Except for third party materials and otherwise stated (see terms and conditions [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)] ), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence.

The material acknowledged below is Proprietary and used under licence (not subject to Creative Commons Licence). Grateful acknowledgement is made to the following sources for permission to reproduce material in this free course:

Course image: ismagilov/123 Royalty Free

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