Gaya APA

Walidi, . (2006). Step by step to speak english (Cet. 1). Yogyakarta: PT Citra Aji Parama.

Gaya MLA

Walidi, . "Step by step to speak english". Cet. 1 Yogyakarta: PT Citra Aji Parama, 2006. Buku Pend. Bahasa Inggris.