Spinage, Clive A., author
Springer, 2012
eBooks
Wiedner, Donald L. Donal Lawrence)
Random House, 1962
Buku Teks
Gilbert, Erik, author
Pearson Educational, 2004
Buku Teks
edited by Phillis M. Martin and Patrick O'Meara
Indiana University Press, 1995
Buku Teks
edited by Bisheshwar Prasad
Asia Public House, 1960
Buku Teks