Vernon, Raymond
Basic Books, 1971
Buku Teks
Delphos, William, 1951-
Business Expert Press, 2012
Buku Teks
edited by Huxley Madeheim, Edward Mark Mazze and Charles S. Stein
Holt, Rinehart and Winston, 1963
Buku Teks
Bryson, George D.
Harper & Brothers, 1961
Buku Teks
Wormald, Avison
Pan Books, 1973
Buku Teks