Gaya APA

al., E. et al (1997,1999,2000,2011). Dasar-dasar Operations Research (Ed. 2). Yogyakarta: BPFE.

Gaya MLA

al., Et. et al. "Dasar-dasar Operations Research". Ed. 2 Yogyakarta: BPFE, 1997,1999,2000,2011. Text.