1. G. Chartrand, M.S. Jacobson, J. Lehel, O.R. Oellermann, S. Ruiz and F. Saba, Irregular Networks, to appear.
2. Some theorems on abstract graphs;Dirac;Proc. London Math. Soc.,1952
3. M.S. Jacobson, L. Kinch and J. Lehel, Sequences generating distinct sums, in preparation.
4. M.S. Jacobson and J. Lehel, A bound for the strength of an irregular network, submitted.
5. Die Theorie der regulären Graphen;Petersen;Acta Math.,1891