共 21 条
[1]
ALLAN S, 1992, JAMA-J AM MED ASSOC, V268, P3338
[3]
ALLWOOD CW, 1992, S AFR MED J, V82, P98
[4]
CHIN J, 1990, B WORLD HEALTH ORGAN, V68, P529
[5]
COLEBUNDERS R, 1987, AM J GASTROENTEROL, V82, P859
[7]
FOSTER S, 1991, LONDON SCH HYGIENE T, V3, P14