| APA | ESPO. (2012, February 15). In Acronym Geek. Retrieved 22:26, February 15, 2012, from http://www.acronymgeek.com/ESPO |
| MLA | "ESPO." Acronym Geek. (2012). Acronym Geek. 15 Feb 2012 <http://www.acronymgeek.com/ESPO>. |
| MHRA | 'ESPO', Acronym Geek, 15 February 2012, <http://www.acronymgeek.com/ESPO> [accessed 15 February 2012] |
| Chicago | "ESPO", http://www.acronymgeek.com/ESPO (accessed February 15, 2012). |
| CBE/CSE | ESPO [Internet]. Acronym Geek; 2012 Feb 15 [cited 2012 Feb 15]. Available from: http://www.acronymgeek.com/ESPO. |
| Bluebook | ESPO, http://www.acronymgeek.com/ESPO (last visited February 15, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, ESPO, http://www.acronymgeek.com/ESPO (optional description here) (as of Feb. 15, 2012, 22:26). |
| AMA | ESPO. Acronym Geek. February 15, 2012, 22:26. Available at: http://www.acronymgeek.com/ESPO. Accessed February 15, 2012, 22:26. |