Mason, Philip, author
Oxford University Press, 1970
Buku Teks
Blalock, Hubert M., author
Prentice-Hall, 1982
Buku Teks
Brown, Ina Corinne
Prentice-Hall, 1973
Buku Teks
Walter, Paul A.F., author
McGraw-Hill, 1952
Buku Teks
edited by Astri Suhrkel and Lela Garner Noble
Frederick A. Praeger, 1977
Buku Teks