[40 years in the service of prophylaxis].
D002031:Bulgaria; D049673:History, 20th Century; D006801:Humans; D009784:Occupational Diseases / Q000175:diagnosis / Q000517:prevention & control; D009787:Occupational Medicine / Q000266:history*; D012106:Research / Q000266:history
40 godini v sluzhba na profilaktikata.