Coombs, William E.
F.W. Dodge Co. , 1958
Buku Teks
Schlatter, Charles F.
John Wiley & Sons, 1960
Buku Teks
Kemp, Patrick S.
Dow Jones-Irwin, Inc., 1970
Buku Teks
Mearns, Ian
Pitman, 1988
Buku Teks
edited by Alfred Rappaport
Prentice-Hall, 1982
Buku Teks