Columba, M. (1926). A study of interests and their relations to other factors of achievement in the elementary school subjects. Catholic Education Press.
Lua i Stíl Chicago (17ú heag.)Columba, Mary. A Study of Interests and Their Relations to Other Factors of Achievement in the Elementary School Subjects. Washington, D.C.: Catholic Education Press, 1926.
Lua MLA (8ú heag.)Columba, Mary. A Study of Interests and Their Relations to Other Factors of Achievement in the Elementary School Subjects. Catholic Education Press, 1926.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.