Ministerstvo na Narodnoto Zdrave, Sofia (Bulgaria); Syyuz na Nauchnite Meditsinski Druzhestva v Bylgariya, Sofia; Nauchno Druzhestvo na Rentgenolozite i Radiolozite, Sofia (Bulgaria); 189 p; Oct 1985; p. 120-121; 6. national congress of roentgenology, radiology and radiobiology; Sofia (Bulgaria); 4-6 Oct 1985; Published in summary form only.