Howell, David C.
Thomson/Wadsworth, 2008
Buku Teks
Kirk, Roger E, author
Sage Publications, 2013
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill , 1981
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill, 1987
Buku Teks
Ferguson, George Andrew, author
McGraw-Hill , 1989
Buku Teks