Marsh, Colin J.
The Falmer Press , 1992
Buku Teks
McNeil, John D., author
Litle Brown, 1977
Buku Teks
King, Imogene M., author
Appletton Century Crofts , 1982
Buku Teks
edited by Limon E. Kattington
Nova Science, 2010
Buku Teks
Davies, Ivor K., author
McGraw-Hill, 1976
Buku Teks