Edgell, David L. (David Lee), Sr., 1938
Routledge, 2016
Buku Teks
Drucker, Peter F. (Peter Ferdinand), 1909-2005, author
Truman Talley Books/Plume, 1992
Buku Teks
Chattell, Alf
Macmillan, 1995
Buku Teks
Sayles, Leonard R., author
Harper & Row, 1971
Buku Teks
Owen, Oliver S., author
Prentice-Hall, 1998
Buku Teks