Edge-Face Total Chromatic Number of Outerplanar Graphs with Delta(G)=6 - C. F. Chang; J. X. Chang; X. C. Lu; Peter Che Bor Lam; J. F. Wang (Computing and Combinatorics, First Annual International Conference, COCOON '95, Xi'an, China, August 24-26, 1995, Proceedings, 1995)