title: Effect of assortative mating and family planning on the incidence of unisexual sibships.
mesh_terms: D003710:Demography; D011153:Population; D011154:Population Characteristics; D012723:Sex; D017678:Sex Distribution; D012737:Sex Factors; D012744:Sex Ratio
keywords: Demographic Factors; Population; Population Characteristics; Sex Distribution; Sex Factors; Sex Preference; Sex Ratio