Watt, Homer A., author
Scott, Foresman, 1932
Buku Teks
Nicolas S. Witschi, editor
Wiley Balckwell, 2014
Buku Teks
edited by Yogita Goyal
Cambridge University Press, 2017
Buku Teks
Hart, James D., author
Oxford University Press, 1986
Buku Referensi
Hart, James D., author
Oxford University Press, 1986
Buku Referensi