Interplay between edge states and simple bulk defects in graphene nanoribbons Liviu Bilteanu, Clement Dutreix, Anu Jagannathan and Cristina Bena Eur. Phys. J. B, 86 5 (2013) 240 Published online: 29 May 2013 DOI: 10.1140/epjb/e2013-30488-6