WALIDI. (2006). Step by Step To Speak English. Klaten: Citra Aji Parama.
Chicago Style aipamenaWALIDI. Step By Step To Speak English. Klaten: Citra Aji Parama, 2006.
MLA aipamenaWALIDI. Step By Step To Speak English. Klaten: Citra Aji Parama, 2006.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.