Schorske, Carl E.
German social democracy
Harvard University Press, 1955
 Buku Teks SO
Sperling, Sebastian
The German social market: a concept of the past?
2006
 Artikel Jurnal
Goldscheider, Calvin
Population, modernization and social structure
Litle Brown, 1971
 Buku Teks SO
Population and social change
edited by D. V. Glass and Roger Revelle
Edward Arnold, 1972
 Buku Teks SO
United Nations
Selected demographic and social characteristics of the world's children and youth
United Nations, 1986
 Buku Teks