Acknowledgements
Every effort has been made to contact copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.
Important: *** against any of the acknowledgements below means that the wording has been dictated by the rights holder/publisher, and cannot be changed.
Grateful acknowledgement is made to the following sources:
Figure 1: © Aleksandr Khakimullin / 123 Royalty Free
Figure 2: © Thinglass / Shutterstock
Figure 3: © Iulia Brovchenko / 123 Royalty Free
Figure 4: © YAY Media AS / Alamy Stock Photo
Figure 5a: © photografier / 123 Royalty Free
Figure 5b: © Varin Rattanaburi / 123 Royalty Free
Figure 6: © popoimagen / iStock / Getty Images Plus
Figure 7: Grant Mitchell. This file is licensed under the Creative Commons Attribution Licence http://creativecommons.org/ licenses/ by/ 3.0/ [Tip: hold Ctrl and click a link to open it in a new tab. (Hide tip)]
Figure 8: © johnkellerman / iStock / Getty Images Plus
Figure 9: University of Wisconsin
References