共 50 条
- [31] CLASSIFICATION OF THE AGRICULTURAL POPULATION IN THE UNITED STATES JOURNAL OF FARM ECONOMICS, 1955, 37 (03): : P511 - P523
- [33] Population Problems in the United States and Canada AMERICAN ECONOMIC REVIEW, 1926, 16 (03): : 511 - 514
- [36] Population Problems in the United States and Canada ECONOMIC JOURNAL, 1926, 36 (144): : 626 - 631
- [38] POPULATION EDUCATION IN UNITED-STATES JOURNAL OF ENVIRONMENTAL EDUCATION, 1977, 8 (04): : 35 - 42