1. J. Akiyama, K. Ando and D. Avis, Miscellaneous properties of equi-eccentric graphs, Ann. Discrete Math. 20 (1984) 13-23.
2. F. Buckley, The central ratio of a graph, Discrete Math. 38 (1982) 17-21.
3. F. Göbel, H. J. Veldman, Even graphs, J. Graph Theory 10 (1986) 225-239.
4. S. F. Kapoor, A. D. Polimeni, C. E. Wall, Degree sets for graphs, Fund. Math. 95 (1977) 189-194.
5. Z. Stanić, Some notes on minimal self-centered graphs, AKCE J. Graphs. Comb. 7 (2010) 97-102.
6. I. E. Zverovich, On a problem of Lesniak, Polimeni and Vanderjagt. Rend. Mat. Appl. 26 (7) (2006) 211-220.