Snider, Harold Wayne
Richard D. Irwin , 1956
Buku Teks
Nelson, Richard L.
Prentice-Hall, 1957
Buku Teks
Nelson, Grant S., author
West Publishing, 1992
Buku Teks
Nelson, Grant S., author
West Publishing, 1994
Buku Teks
Lawler, J. John, author
Foundation Press, 1940
Buku Teks