Jacobsen, Kathyn, author
Jones & Bartlett Learning, 2012
Buku Teks
Jacobsen, Kathryn H., author
Jones & Bartlett Learning, 2017
Buku Teks
Denscombe, Martyn, author
Open University Press, 2012
Buku Teks
Sophie Laws, Caroline Harper, Nicola JOnes, Rachel Marcus
SAGE, 2013
Buku Teks
French, Sally, author
Butterworth-Heinemann, 2001
Buku Referensi