共 16 条
[3]
FERNANDEZ EW, 1975, 38 US BUR CENS TECHN
[4]
Fletcher R., 1982, CLIN EPIDEMIOLOGY ES
[6]
HAUB C, 1981, INTERCOM, V9, P8
[9]
HERNANDEZ J, 1973, SOC SCI QUART, V53, P671