1. Ahmed, Adel, Dwyer, Tim, Forster, Michael, Fu, Xiaoyan, Ho, Joshua, Hong, Seok-Hee, Koschützki, Dirk, et al., 2006. GEOMI: GEOmetry for maximum insight. In: Healy, Patrick, Nikolov, Nikola S. (Eds.), Graph Drawing, vol. 3843. Springer Berlin Heidelberg, Berlin, Heidelberg, pp. 468–479.
2. Graph-based methods for analysing networks in cell biology;Aittokallio;Briefings in Bioinformatics,2006
3. APTA, 2009. Defining Transit Areas of Influence. American Public Transportation Association, Document Number: APTA SUDS-UD-RP-001-09. (accessed 04.02.12).
4. APTA, 2011. Public Transit Ridership Report, Third Quarter 2011 (www.apta.com). .
5. The connectivity index of a weighted graph;Araujo;Linear Algebra and its Applications,1998