Bauer, P.T.
Frederick A. Praeger, 1961
Buku Teks
editors, Subroto Roy and William E. James
Sage Publications, 1992
Buku Teks
Hanson, A.H.
Oxford University Press, 1966
Buku Teks
Mahendra Dev, S.
Oxford University Press, 2008
Buku Teks
Palvia, Chand Mal
Institute of Social Studies, 1953
Buku Teks