Steve J. Hothersall, Mike Maas-Lowit
Learning Matters Ltd., 2010
Buku Teks
Trevithick, Pamela, author
McGraw-Hill , 2012
Buku Teks
McCoyd, Judith L.M, author
Roudledge, 2016
Buku Teks
Coppock, Vicki, author
SAGE, 2010
Buku Teks
Seden, Janet, author
Open University Press, 2005
Buku Teks