Cambridge University Press, 1995
eBooks
Aho, Alfred V.
Prentice-Hall, 1972
Buku Teks
Ratna Iriani
Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Indonesia, 1987
UI - Skripsi (Membership)
edited by Masaru Tomita
Kluwer Academic, 1991
Buku Teks
Roberts, Ian
Oxrord University Press, 2007
Buku Teks