In: Newsletter of the Special Interest Group on Petri Nets and Related System Models, pages 21-27. February 1980.
Abstract: Many people have indicated that some of the early classic papers on Petri nets are difficult to obtain. In the United States much research is supported by grants and contracts from the U.S. government and so copies of these research reports are filed with the government. The National Technical Information Service (Department of Commerce) provides access to most of these reports.