THE METHODOLOGY OF COMPLEX SOCIAL HYGIENIC INVESTIGATION OF VARIOUS GROUPS OF POPULATION AND FAMILIES (IN MEMORIAM OF PROFESSOR O. V. GRININA) ArticleKicha D.I., Nechaev V.S., Stepanova S.M.Problemy sotsial'noi gigieny, zdravookhraneniia i istorii meditsiny. Том 27. 2019. С. 328-332