Spector, Ivar
Van Nostrand Reinhold, 1949
Buku Teks
Stephan, John J.
Stanford University Press, 1994
Buku Teks
Reshetar, JR, John S.
Priceton University Press, 1952.
Buku Teks
McVey, Ruth Thomas, author
Cornell university, 1962, 1957.
Buku Teks
Boyle, Peter G., author
Routledge, 1993
Buku Teks