| APA | ISDN. (2012, February 9). In Acronym Geek. Retrieved 20:14, February 9, 2012, from http://www.acronymgeek.com/ISDN |
| MLA | "ISDN." Acronym Geek. (2012). Acronym Geek. 9 Feb 2012 <http://www.acronymgeek.com/ISDN>. |
| MHRA | 'ISDN', Acronym Geek, 9 February 2012, <http://www.acronymgeek.com/ISDN> [accessed 9 February 2012] |
| Chicago | "ISDN", http://www.acronymgeek.com/ISDN (accessed February 9, 2012). |
| CBE/CSE | ISDN [Internet]. Acronym Geek; 2012 Feb 9 [cited 2012 Feb 9]. Available from: http://www.acronymgeek.com/ISDN. |
| Bluebook | ISDN, http://www.acronymgeek.com/ISDN (last visited February 9, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, ISDN, http://www.acronymgeek.com/ISDN (optional description here) (as of Feb. 9, 2012, 20:14). |
| AMA | ISDN. Acronym Geek. February 9, 2012, 20:14. Available at: http://www.acronymgeek.com/ISDN. Accessed February 9, 2012, 20:14. |