Nagle, David (May 2009). "Track-Able"(PDF). An Cosantóir. Vol. 69, no. 4. pp. 14–15. Archived from the original(PDF) on 10 September 2015. Retrieved 26 January 2016.
Nagle, David (May 2009). "Track-Able"(PDF). An Cosantóir. Vol. 69, no. 4. pp. 14–15. Archived from the original(PDF) on 10 September 2015. Retrieved 26 January 2016.