Runge, Laura L.
Cambridge University Press, 1997
eBooks
Stratton, Florence
Routledge, 1994
Buku Teks
McDowell, Linda, 1949-
Wiley-Blackwell, 2013
Buku Teks
Stearns, Peter N.
Rontledge, 2006
Buku Teks
edited by Jo Little, Linda Peake, and Pat Richardson
Macmillan, 1988
Buku Teks