Sage Periodeicals Press, 1992
Majalah, Jurnal, Buletin
Riggs, Fred W., author
Houghton Miffiln, 1964
Buku Teks
Corson, John J., author
McGraw-Hill , 1963
Buku Teks
Viola, Richard H.
W.B. Saunders Company, 1977
Buku Teks
Riggs, Fred W., author
Rajawali, 1985, 1988
Buku Teks