Salaman, Redclife N.
Potato varieties
Cambridge University Press, 2014
 Buku Teks
James, William
The varieties of religious experience
Mentor Books, 1958
 Buku Teks
Hickey, Raymond, 1954-
A dictionary of varieties of English
Wiley Blackwell, 2014
 Buku Referensi
Moran, Marie
Identity and capitalism
SAGE, 2015
 Buku Teks
Risking capitalism
edited by Susanne Soederberg
Emerald, 2016
 eBooks