[Medical security system in Bulgaria: retrospections and prospects].
Apostolov
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D002031:Bulgaria; D049692:History, Early Modern 1451-1600; D049691:History, Medieval; D049711:History, Modern 1601-; D007341:Insurance / Q000266:history; D007348:Insurance, Health / Q000266:history*; D011634:Public Health / Q000266:history*; D012943:Social Security / Q000266:history*; D013222:State Medicine / Q000266:history*