Ducat, Graig R.
West Publishing Company, 1978
Buku Teks
Ducat, Craig R, author
Wardsworth Cengage Learning, 2013
Buku Teks
Marmor, Andrei, author
Oxford University Press, 1995
Buku Teks
London: Kluwer Academic Publishers, 1990,
Buku Referensi
edited by Patrick Nerhot
Kluwer Academic Publishers, 1990
Buku Referensi