| APA | GPPO. (2012, February 15). In Acronym Geek. Retrieved 18:38, February 15, 2012, from http://www.acronymgeek.com/GPPO |
| MLA | "GPPO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/GPPO>. |
| MHRA | 'GPPO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/GPPO> [accessed 15 February 2012] |
| Chicago | "GPPO", http://www.acronymgeek.com/GPPO (accessed February 15, 2012). |
| CBE/CSE | GPPO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/GPPO. |
| Bluebook | GPPO, http://www.acronymgeek.com/GPPO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, GPPO, http://www.acronymgeek.com/GPPO (optional description here) (as of Feb. 15, 2012, 18:38). |
| AMA | GPPO. Acronym Geek. February 15, 2012, 18:38. Available at: http://www.acronymgeek.com/GPPO. Accessed February 15, 2012, 18:38. |