The idea to finance healthcare on the fund principle was launched for the first time in the Principality of Bulgaria in 1878, in the theoretical work "Considerations on the Establishment of the Medical Sector in Bulgaria" written by Dr. Dimitar Mollov. In it the author introduced the thesis to raise contributions in a health fund from a specially designated land fund which would be cultivated by the population. The resources from this fund would thus cover fully or partially the expenditures for healthcare to the benefit of the insured persons. In 1936 was published the book "Comprehensive Health Service" written by Dr. Zachary Botchev. The idea was to establish a comprehensive and accessible for the entire population system of healthcare to be financed by an insurance fund and to be managed in a democratic and decentralized way with the wide participation of the public and of the professional associations.