Landis, Paul H.
Ginn and Company, 1961
Buku Teks
edited by G. N. Appell and Leigh R. Wright
Cornell University, 1978
Buku Referensi
Happ, H.H.
John Wiley & Sons, 1980
Buku Teks
Miller, Robert H., author
McGraw-Hill, 1994
Buku Teks
Lentner, Howard H., author
Routledge, 2004
Buku Teks