Fertility Fertility, Human 5 Family planning 4 Demography 3 Human 3 Infertility 3 Reproduction 3 Birth control 2 Birth intervals 2 Congresses 2 Dissertations, Academic (Ph.D) 2 Family size 2 Population control 2 Working paper 2 Abortion 1 Abortion in animals 1 Abortion, Veterinary 1 Aetiology 1 Animal Reproduction and Embryology, (New March 2000) 1 Animals, Domestic 1 Cattle 1 Demographic transition 1 Developing countries 1 Diagnosis 1 Diagnosis of Animal Diseases, (New March 2000) 1 Differential diagnosis 1 Diffusion 1 Disease control 1 Disease prevention 1 Economic condition 1