Acknowledgements

This course was written by Arosha K. Bandara.

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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 course:

Images

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Figure 2 © Bob Lord - Licensed under Creative Commons Attribution-Share Alike 3.0 via Wikimedia Commons - http://commons.wikimedia.org/wiki/File:Enigma-plugboard.tif#mediaviewer/File:Enigma-plugboard.tif

Figure 3 © agsandrew (via Shutterstock Photos)

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Figure 12 © Vertigo3d (via iStock Photo)

Audio visual

2.1 and 2.2 © The Open University

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