Ducat, Craig R
Wardsworth Cengage Learning, 2013
Buku Teks
Marmor, Andrei
Oxford University Press, 1995
Buku Teks
London: Kluwer Academic Publishers, 1990,
Buku Referensi
edited by Patrick Nerhot
Kluwer Academic Publishers, 1990
Buku Referensi
Andreae, J.P. Pockema
A.W. Sijthoff, 1948
Buku Teks