Gaya APA
Kelly, A, M, G, R, E, G, L, M. (1980).
The William Lowell Putnam mathematical competition problems and solutions : 1938-1964 .
United State of America:
The Mathematical Assosiation of America.
Gaya MLA
Kelly, A., M., Gleason,, R., E., Greenwood,, L., M..
"The William Lowell Putnam mathematical competition problems and solutions : 1938-1964".
United State of America:
The Mathematical Assosiation of America,
1980.
Text.