Burton, Rosemary, author
Pitman, 1995
Buku Teks
Boniface, Brian G, author
Routledge, 2016
Buku Teks
Eastwood, John, author
Oxford University Press, 1994
Buku Teks
Getis, Arthur, author
McGraw-Hill Higher Education, 2009
Buku Teks
Northam, Ray M., author
John Wiley & Sons, 1979
Buku Teks