Gaya APA

Lim, M., Clooney, R. (2004). Up in the Sky (Cet. 1). Hongkong: Longman Hong Kong Education.

Gaya MLA

Lim, Marian., Clooney, Ruth. "Up in the Sky". Cet. 1 Hongkong: Longman Hong Kong Education, 2004. Text.