Gaya APA

WALIDI, . (2006). STEP BY STEP TO SPEAK ENGLISH (Cet. 1). Yogyakarta: CITRA AJI PARAMA.

Gaya MLA

WALIDI, . "STEP BY STEP TO SPEAK ENGLISH". Cet. 1 Yogyakarta: CITRA AJI PARAMA, 2006. Text.