Gaya APA

Setiorini, D., Swasono, E, P. (2015). Acoustic Analysis of Vowels Produced by Efl Students in UIN Sunan Ampel Surabaya . Surabaya: Fakultas Adab dan Humaniora UINSA.

Gaya MLA

Setiorini, Dewi., Swasono, Endratmo, Pilih. "Acoustic Analysis of Vowels Produced by Efl Students in UIN Sunan Ampel Surabaya". Surabaya: Fakultas Adab dan Humaniora UINSA, 2015. Skripsi.