Bollinger, Lee C., author
Oxford University Press, 2010
Buku Teks
Hill, David T., author
Pustaka Sinar Harapan, 1995
Buku Teks
Hill, David T., author
Pustaka Sinar Harapan, 1995
Buku Teks
Gurton, Annie, author
Prentice-Hall, 1998
Buku Teks
Russel Sage Foundation, 2000
Buku Teks