Wanlass, Lawrence C., author
Appleton-Century-Crofts, 1953
Buku Teks
Sankar Muthu
Cambridge University Press, 2014
Buku Teks
Routledge, 2000
Buku Teks
Sharma, R.P., author
Sterling Publishers Private, 1984
Buku Teks
Scott, Andrew M., author
Holt, Rinehart & Winston, 1959
Buku Teks