McKellips, R. L. (1977). The role of the language and operations of sets in the elementary arithmetic program. University of the Philippines Library.
Lua i Stíl Chicago (17ú heag.)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.
Lua MLA (9ú heag.)McKellips, Raymond Leon. The Role of the Language and Operations of Sets in the Elementary Arithmetic Program. University of the Philippines Library, 1977.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.