Bhatt, P., author
Longman Scientific and Technical, 1990
Buku Teks
edited by M. Ivanyi and M. Skaloud
Springer-Verlag, 1992
Buku Teks
Godoy, Luis A., author
Pergamon Press, 1996
Buku Teks
Marshall, W.T.
Pitman, 1978
Buku Teks
Vazirani, V.N., author
Khanna Publishers, 1979
Buku Teks