A. Jurek, S. Greenland, and G. Maldonado. International journal of epidemiology, 37 (2):
382-5(April 2008)4980<m:linebreak></m:linebreak>LR: 20081121; JID: 7802871; 2008/01/09 aheadofprint; ppublish;.
J. Bigham, M. Hutcheon, D. Patrick, and A. Pollard. Canada Communicable Disease Report = Relevé Des Maladies Transmissibles Au Canada, 27 (2):
13--8(January 2001)PMID: 11227821.