Nirala, D. K. (2013). Better English pronunciation. Anmol Publication.
Chicago Style aipamenaNirala, Dileep Kumar. Better English Pronunciation. New Delhi: Anmol Publication, 2013.
MLA aipamenaNirala, Dileep Kumar. Better English Pronunciation. Anmol Publication, 2013.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.