[25 years hygiene and epidemiology services in the People's Republic of Bulgaria].
D002031:Bulgaria; D004813:Epidemiology / Q000266:history*; D006666:History of Medicine; D011634:Public Health / Q000266:history*; D011635:Public Health Administration / Q000266:history; D012499:Sanitation / Q000266:history
25 let gigieno-épidemiologicheskogo dela v Narodnoĭ Respublike Bolgarii