Boughey, Arthur S.
McMillan Publisher, 1975
Buku Teks
Cambridge University Press, 2002
eBooks
Griffin, Ricky W.
Pearson Education International, 2006
Buku Teks
Griffin, Ricky W.
Prentice-Hall, 1993
Buku Teks
Griffin, Ricky W.
Prentice-Hall, 1999
Buku Teks