title: Problems of contamination in panel surveys: a brief report on an independent sample, Taiwan, 1970.
mesh_terms: D000328:Adult; D000367:Age Factors; D001290:Attitude; D003268:Contraception Behavior; D003276:Contraceptives, Oral; D003710:Demography; D005191:Family Characteristics; D005193:Family Planning Services; D005260:Female; D005298:Fertility; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D007434:Intrauterine Devices; D011247:Pregnancy; D012494:Sampling Studies; D013624:Taiwan
chemical_list: D003276:Contraceptives, Oral