Aerobic bacteria , chlamydia trachomatis , pneumocystis carinii and cytomegalovirus as agents of severe pneumonia in small infants - Ejzenberg, B; Melles, H; Melles, C; Dias, R; Baldacci, Evandro Roberto; Okay, Yassuhiko (Revista do Instituto de Medicina Tropical de Sao Paulo, 1996)