Gaya APA

Walidi, . (2006). Step by Step to Speak English (Cet. 3). Yogyakarta: PT CITRA AJI PARAMA.

Gaya MLA

Walidi, . "Step by Step to Speak English". Cet. 3 Yogyakarta: PT CITRA AJI PARAMA, 2006. 400 Bahasa.