[PROFESSOR I. R. PETROV (ON THE 70TH ANNIVERSARY OF HIS BIRTH)].
D000846:Anniversaries and Special Events; D049672:History, 19th Century; D049673:History, 20th Century; D036801:Parturition
BIOGRAPHIES
PROFESSOR I. R. PETROV (K 70-LETIIU SO DNIA ROZHDENIIA)