Devito, Joseph A.
Harper & Row Publishers, 1986
Buku Teks
Devito, Joseph A.
Pearson education limited , 2014
Buku Teks SO
Hartley, Peter, 1946-
Roudledge, 1993
Buku Teks SO
Condon, John C.
Macmillan, 1977
Buku Teks
Floyd, Kory
Mc Graw Hill, 2012
Buku Teks SO