共 50 条
- [41] INCREASED HOSPITAL BIRTHS IN THE UNITED-STATES JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION, 1955, 159 (10): : 1021 - 1021
- [43] PORTRAIT OF UNITED-STATES FERTILITY SHOWS AVERAGE NUMBER OF BIRTHS, FAMILY-SIZE DIFFERENCES ARE SHRINKING FAMILY PLANNING PERSPECTIVES, 1985, 17 (01): : 36 - 37
- [44] PLANNED AND UNPLANNED BIRTHS IN THE UNITED-STATES .2. THE DECLINE IN UNWANTED FERTILITY, 1971-1976 FAMILY PLANNING PERSPECTIVES, 1981, 13 (02): : 70 - 72
- [48] Temporal trends in the frequency of twins and higher-order multiple births in Canada and the United States BMC Pregnancy and Childbirth, 12
- [49] THE CHANGING PATTERN OF MULTIPLE BIRTHS IN THE UNITED-STATES - MATERNAL AND INFANT CHARACTERISTICS, 1973 AND 1990 OBSTETRICS AND GYNECOLOGY, 1994, 84 (01): : 101 - 106