http://www.ncbi.nlm.nih.gov/pubmed/18364611
South Med J. 2008 Feb; 101(2):129-37
http://link.springer.com/article/10.1007%2Fs11222-007-9031-1#
Statistics and Computing. December 2007; 17(4): 381-393.
http://www.ncbi.nlm.nih.gov/pubmed/17825023
Biometrics. 2007 Sep; 63(3):935-41
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2567827/
Epidemiology. 2007 September; 18(5): 552-560
http://smm.sagepub.com/content/16/2/167.abstract
Stat Methods Med Res. April 2007; vol. 16, no. 2, 167-184
http://www.sciencedirect.com/science/article/pii/S0167947305003099
Computational Statistics & Data Analysis. 15 Nov 2006; 51(2): 1197-1212
http://www.jahonline.org/article/PIIS1054139X04000990/abstract
Journal of Adolescent Health. October 2004; Volume 35, Issue 4, Pages 321-328
http://www.jahonline.org/article/PIIS1054139X04000539/abstract
J Adolesc Health. 2004 Oct; 35(4):345.e17-26
http://www.ncbi.nlm.nih.gov/pubmed/12687653
Stat Med. 2003 Apr 30; 22(8):1235-54
