Thema
Time Factors
Journal Article
369
Demographic Factors
353
Population
353
Population Dynamics
349
Research Methodology
302
Studies
276
Comparative Studies
275
Comparative Study
244
Family Planning
201
Developing Countries
183
Developed Countries
165
Research Report
152
Biology
147
Population Characteristics
135
Contraception
129
Physiology
127
Americas
126
Age Factors
112
North America
106
Diseases
103
Research Support, Non-U.S. Gov't
101
Reproduction
96
Health
91
Northern America
84
Asia
80
United States
78
Longterm Effects
72
Fertility
70
Economic Factors
65
Behavior
63
Socioeconomic Factors
57
Nutrition
56
Europe
54
Fertility Measurements
53
Klinische Studie
48
Measurement
48
Infant Nutrition
47
Pregnancy
47
Contraceptive Methods
46
Latin America
46
Contraceptive Agents, Female
44
Clinical Research
41
Cultural Background
41
Ethnic Groups
41
Contraceptive Usage
40
Youth
40
Breast Feeding
39
Socioeconomic Status
39
Treatment
39
mehr ...