Saunders, Rebecca
Capstone , 2000
Buku Teks
Chase, Stuart, author
Harper & Row Publisher, 1968
Buku Teks
Slater, Robert, 1943- author
McGraw-Hil, 2009
Buku Teks
December, John, author
Sams, 1994
Buku Teks
Steinhoff, Dan, author
McGraw-Hill, 1979
Buku Teks