Gaya APA

Puryani, ., Ristono, A. (2012). Penelitian operasional (Ed.1, Cet.1). Yogyakarta: Graha Ilmu.

Gaya MLA

Puryani, ., Ristono, Agus. "Penelitian operasional". Ed.1, Cet.1 Yogyakarta: Graha Ilmu, 2012. Textbook.