Gaya APA

Irwin, D, M. (1980). Observational strategies for child study . New York: Holt, Rinehart and winston,Inc.

Gaya MLA

Irwin, D., Michelle. "Observational strategies for child study". New York: Holt, Rinehart and winston,Inc, 1980. Hibah Buku Dra. Anita Lestari,.