Open-air ethnographic museums are the most recent museological institutions in Hungary. Their problems involve the transfer and protection of buildings as well as the treatment of art objects reflecting the life style of a given period; in each phase the cooperation of museologists, monuments experts, and restorers is being encouraged. Under such open-air conditions the physical, chemical, and biological stability of ethnographic monuments and their furnishings must be insured in such a way that the principles of display do not compromise standards of good museology. See also AATA 22-399 for reference to book.