Kraftcheck D J, Paterson J M, Alton B, Cheung W, Goebel C, Kennedy W, Kraftcheck D, Levy R, Neimanis I, Ohayon J, Peer J, Wahi S, Paterson J M
Department of Family Medicine, St. Joseph's Healthcare, McMaster University, Hamilton.
Can Commun Dis Rep. 2003 Nov 15;29(22):189-94.