Mouton Publishers, 1976
Buku Teks
Foster, George M., author
John Wiley & Sons, 1978
Buku Teks
Pool, Robert, author
McGraw-Hill Open University Press, 2005
Buku Teks
Joralemon, Donald, author
Routledge, 2017
Buku Teks
McElroy, Ann
Westview Press, 1996
Buku Teks