APA Style

Puryani, ., Ristono, A. (2012). Penelitian operasional (ed. 1). Yoyakarta: Graha Ilmu.

MLA Style

Puryani, ., Ristono, Agus. "Penelitian operasional". ed. 1 Yoyakarta: Graha Ilmu, 2012. Text.