Davies, Ivor K., author
McGraw-Hill, 1973
Buku Teks
Schlecht, Phillip C., 1937-, author
Jossey-Bass, 1997
Buku Teks
Morphet, Edgar L. (Edgar Leroy), 1895- , author
Prentice-Hall, 1982
Buku Teks
Survey, 1964
Buku Teks
Snowden, Petre E.
McGraw-Hill , 1998
Buku Teks