Formacion, P. S. Inquiry slides for teaching ecology in the elementary grades.
Lua i Stíl Chicago (17ú heag.)Formacion, Placida S. Inquiry Slides for Teaching Ecology in the Elementary Grades. Quezon City, 1973.
Lua MLA (9ú heag.)Formacion, Placida S. Inquiry Slides for Teaching Ecology in the Elementary Grades.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.