| APA | PDU. (2012, February 13). In Acronym Geek. Retrieved 20:59, February 13, 2012, from http://www.acronymgeek.com/PDU |
| MLA | "PDU." Acronym Geek. (2012). Acronym Geek. 13 Feb 2012 <http://www.acronymgeek.com/PDU>. |
| MHRA | 'PDU', Acronym Geek, 13 February 2012, <http://www.acronymgeek.com/PDU> [accessed 13 February 2012] |
| Chicago | "PDU", http://www.acronymgeek.com/PDU (accessed February 13, 2012). |
| CBE/CSE | PDU [Internet]. Acronym Geek; 2012 Feb 13 [cited 2012 Feb 13]. Available from: http://www.acronymgeek.com/PDU. |
| Bluebook | PDU, http://www.acronymgeek.com/PDU (last visited February 13, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, PDU, http://www.acronymgeek.com/PDU (optional description here) (as of Feb. 13, 2012, 20:59). |
| AMA | PDU. Acronym Geek. February 13, 2012, 20:59. Available at: http://www.acronymgeek.com/PDU. Accessed February 13, 2012, 20:59. |