Cambridge University Press, 2015
eBooks
edited by Jeyanth Asheervath and Dorothy R. Blevins
Appleton-Century-Crofts, 1986.
Buku Referensi
Sage Publications, 2012
eBooks
Sen, B., author
Martinus Nijhoff, 1965
Buku Teks
edited by Jeffrey J. Magnavita
John Wiley & Sons, 2003
Buku Teks