APA Style

Ritchie, A., Haas, C. (2008). It's time to sleep, you crazy sheep! : waktunya tidur, domba nakal! . Jakarta, Indonesia: Erlangga For Kids.

MLA Style

Ritchie, Alison., Haas, Cornelia. "It's time to sleep, you crazy sheep! : waktunya tidur, domba nakal!". Jakarta, Indonesia: Erlangga For Kids, 2008. Text.