title: Cross-section studies as predictors of trends in birth rates: a note on Ekanem's results.
mesh_terms: D001723:Birth Rate; D003710:Demography; D003906:Developing Countries; D005298:Fertility; D006801:Humans; D007182:Income; D008722:Methods; D012044:Regression Analysis; D012959:Socioeconomic Factors; D013223:Statistics as Topic; D013997:Time Factors