Pittman, R. S. (1951). Notes on the dialect geography of the Philippine Islands. Summer Institute of Linguistics.
Chicago-referens (17:e uppl.)Pittman, Richard S. Notes on the Dialect Geography of the Philippine Islands. Glendale, Calif: Summer Institute of Linguistics, 1951.
MLA-referens (9:e uppl.)Pittman, Richard S. Notes on the Dialect Geography of the Philippine Islands. Summer Institute of Linguistics, 1951.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.