1. ANSI/X3/SPARC {1975}. "Intrim Report NASI/X3/SPARC Study Group on Data Base Management Systems " FDT7(2). ANSI/X3/SPARC {1975}. "Intrim Report NASI/X3/SPARC Study Group on Data Base Management Systems " FDT7(2).
2. }. "A Great Debate," CACM17, 360. Ashenhurst, R. L., and Vonderohe, R. H. {1975}. "A Hierarchical Network;Ashenhurst R.;Datamation,1974
3. System R
4. Data structure diagrams
5. The programmer as navigator