共 32 条
[13]
PIKE MC, 1970, BRIT J PREV SOC MED, V24, P42
[15]
ROBINSON DA, 1981, BRIT MED J, V282, P1584, DOI 10.1136/bmj.282.6276.1584
[19]
SVEDHEM A, 1981, J INFECTION, V3, P37, DOI 10.1016/S0163-4453(81)92261-1