Most graph labeling methods trace their origin to one introduced by Alex Rosa, through the paper "On certain valuations of the vertices of a graph", which was presented in the International Symposium, held in Rome, July 1966,Gordon and Breach, N.Y. and Dunod Paris (1967) 349-355, or one given by R.L.Graham and N.J.A. Sloane, through the paper "On additive bases and harmonious graphs", SIAM J. Alg. Discrete Meth., 1 (1980) 382-404. Labeled graphs became a very useful tool for treating many problems in different branches of science, e.g. Electrical Networks, Coding Theory, Astronomy, X-Ray...