Credits

© BSIP

© BSIP/ASTIER

© BSIP/BELMONTE

© BSIP/JOSE OTO

© BSIP/SCOTT CAMAZINE

© Astoria/Fotolia.com

© Bea Busse/Fotolia.com

© Udo Kroener/fotolia.com

© Radu Razuan/fotolia.com

© Flashon studio/fotolia.com

© Maria Brztowska/Fotolia.com

© Orangeline Media/Fotolia.com

© daniel sainthorant/fotolia.com

© P. MARAZZI/SPL/Cosmos

© JE Grey et al, BMJ 2006 ; 332 :347-350. Reproduced with the kind permission of the authors.

© Ayello et al, 2005. Reproduced with the permission of Lippincott Williams Wilkins (lww.com)