Agger, Ben, author
Falmer Press, 1992
Buku Teks
edited by Roger Owen & Bob Sutcliffe
Longman, 1972
Buku Teks
Hall, Jerome, author
Oceana Publication, 1958
Buku Teks
Karauba, Anatolij A., author
Springer-Verlag, 1993
Buku Teks
Adams, William W., author
Prentice-Hall, 1976
Buku Teks