Βιβλιογραφική Τεκμηρίωση:
Gregory D. Ayers, Eliot T. McKinley, Ping Zhao, Jordan M. Fritz, Rebecca E. Metry, Brenton C. Deal, Katrina M. Adlerz, Robert J. Coffey, H. Charles Manning
J Ultrasound Med.
Author manuscript; available in PMC 2010 August 23.
Published in final edited form as: J Ultrasound Med. 2010 June; 29(6): 891–901.
Mark Lunt
Am J Epidemiol. 2014 January 15; 179(2): 226–235. Published online 2013 October 10.doi: 10.1093/aje/kwt212