Arto Salomaa. On some recent problems concerning developmental languages. In Karl-Heinz Böhling, Klaus Indermark, editors, 1. Fachtagung über Automatentheorie und Formale Sprachen, Bonn, 9.-12. Juli 1973, Gesellschaft für Informatik (GI). Volume 2 of Lecture Notes in Computer Science, pages 23-34, Springer, 1973.
Abstract is missing.