Cofman, J. (1995). Numbers and shapes revisited: More problems for young mathematicians. Clarendon Press.
Chicago-referens (17:e uppl.)Cofman, Judita. Numbers and Shapes Revisited: More Problems for Young Mathematicians. Oxford: Clarendon Press, 1995.
MLA-referens (9:e uppl.)Cofman, Judita. Numbers and Shapes Revisited: More Problems for Young Mathematicians. Clarendon Press, 1995.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.