APA
Funk W. &. L. N., . (1970). 30 days to a more powerful vocabulary. Pocket Books, New York: .
Chicago
Funk Wilfred & Lewis Norman, . 1970. 30 days to a more powerful vocabulary. Pocket Books, New York: .
Harvard
Funk W. &. L. N., . (1970). 30 days to a more powerful vocabulary. Pocket Books, New York: .
MLA
Funk Wilfred & Lewis Norman, . 30 days to a more powerful vocabulary. Pocket Books, New York: . 1970.