Swets and Zertlinger , 1992
Buku Teks
Stanton, Hazel M.
University, 1933
Buku Teks
Leighton, Jacqueline P., author
Oxford University Press, 2017
eBooks
Wragg, Ted, author
Routledge, 1997
Buku Teks
Sudarwan Danim, author
Kencana Prenada Media, 2011
Buku Teks