Heisel, Donald, author
Population Council, 1998
Buku Teks
edited by Anrudh Jain
Population Council, 1998
Buku Teks
Rosen, George, author
University California Press , 1966
Buku Teks
Epstein, T. Scarlett, author
Manchester University Press , 1962
Buku Teks
Rosinger, Lawrence K., author
Macmillan, 1950
Buku Teks