APA
P.R. Twentyman, . (1999). British Journal of Cancer. New York: pergamon press.
Chicago
P.R. Twentyman, . 1999. British Journal of Cancer. New York: pergamon press.
Harvard
P.R. Twentyman, . (1999). British Journal of Cancer. New York: pergamon press.
MLA
P.R. Twentyman, . British Journal of Cancer. New York: pergamon press. 1999.