Kohn, Caroline
Stuttgart JB Metzlersche 1966
Buku Teks
Barrow, Colin, author
John Wiley & Sons, 2001
Buku Teks
Barkin, J. Samuel, 1965-, author
Cambridge University Press, 2010
Buku Teks
Layder, Derek
Macmillan, 1990
Buku Teks
Okoye, Adaeze, author
NY Routledge, 2017
Buku Teks