Kumar, A. (1999). Learner performance in distance education. Commonwealth.
Lua i Stíl Chicago (17ú heag.)Kumar, Anil. Learner Performance in Distance Education. New Delhi: Commonwealth, 1999.
Lua MLA (9ú heag.)Kumar, Anil. Learner Performance in Distance Education. Commonwealth, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.