Stott, Philip
Allen & Unwin, 1981
Buku Referensi
Wolf, Hans Julius
University of Oklahoma Press, 1978
Buku Teks
Campbell, Lyle, author
Edinburgh University Press , 2013
Buku Teks
Young, Robert, 1950-, author
UK Malden, MA John Wiley & Sons, Inc., 2016
Buku Teks
Losee, John, author
Oxford University Press, 1980
Buku Teks