Giorgio Ausiello, Alessandro D Atri, Marco Protasi. On the Structure of Combinatorial Problems and Structure Preserving Reductions. In Arto Salomaa, Magnus Steinby, editors, Automata, Languages and Programming, Fourth Colloquium, University of Turku, Finland, July 18-22, 1977, Proceedings. Volume 52 of Lecture Notes in Computer Science, pages 45-60, Springer, 1977.
Abstract is missing.