Gaya APA

Swanson, C, P., Green, G, F. (1974). Elementary school mathematics activities and materials . Massachusetts: Massachusetts: D.C. Heath and Co.; 1974..

Gaya MLA

Swanson, Carl, P.., Green, George, F.. "Elementary school mathematics activities and materials". Massachusetts: Massachusetts: D.C. Heath and Co.; 1974., 1974. Text.