1. Abello J., M.R. Fellows and J.C. Stillwell, On the complexity and combinatorics of covering finite complexes, Australasian Journal of Combinatorics
4 (1991), 103–112 351
2. Brandstädt, Andreas, Special graph classes-A survey, Schriftenreihe des Fachsbereichs Mathematik, SM-DU-199 (1991), Universität Duisburg Gesamthochschule. 352
3. Chang, G. J. and D. Kuo, The L(2, 1)-labeling problem on graphs, SIAM J. Disc. Math.
9, (1996), pp. 309–316. 352, 353
4. Griggs, J. R. and R. K. Yeh, Labelling graphs with a condition at distance 2, SIAM J. Disc. Math.
5, (1992), pp. 586–595. 350, 353, 356
5. Kratochvíl, Jan, Regular codes in regular graphs are difficult, Discrete Math.
133 (1994), 191–205 351