McKellips, R. L. (1977). The role of the language and operations of sets in the elementary arithmetic program. University of the Philippines Library.
Citazione stile Chigago Style (17a edizione)McKellips, Raymond Leon. The Role of the Language and Operations of Sets in the Elementary Arithmetic Program. Quezon City: University of the Philippines Library, 1977.
Citatione MLA (9a ed.)McKellips, Raymond Leon. The Role of the Language and Operations of Sets in the Elementary Arithmetic Program. University of the Philippines Library, 1977.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.