Petersen, William, author
Macmillan, 1961
Buku Teks
Petersen, William, author
Macmillan, 1969
Buku Teks
Petersen, William, author
Macmillan, 1969
Buku Teks
edited by Jane A. Menken, Ann K. Blanc, Cynthia B. Lloyd
The population council, 2002
Buku Teks
by W. D. Borrie [and others]
UNESCO, 1957
Buku Teks