Chambers, Edward J., author
Prentice-Hall, 1961
Buku Teks
Stekler, Herman O., author
Frederick A. Praeger, 1970
Buku Teks
Gordon, Robert Aaron, author
Harper & Brothers, 1952
Buku Teks
Bowers, David A., author
Addison-Wesley, 1985
Buku Teks
Theil, Henri, author
North-Hollad Pub., 1966
Buku Teks