Buskirk, Richard Hobart, 1927-
Holt Rinehart, 1970
Buku Teks
Lovelock, Christopher H.
Pearson Education international, 2002
Buku Teks
Enis, Ben M.
Goodyear, 1974
Buku Teks
Kotler, Philip
Prentice-Hall, 1996
Buku Teks
Kotler, Philip
Prentice-Hall, 2001
Buku Teks