Gaya APA

Harness, C. (2015). They're off! The story of The pony express (cetakan ke 1). : Kepustakaan Populer Gramedia.

Gaya MLA

Harness, Cheryl. "They're off! The story of The pony express". cetakan ke 1 : Kepustakaan Populer Gramedia, 2015. Text.