GSYSR: A Relational Database Interface for Graphics. - Jose Luis Becerril; Ramón Casajuana; Raymond A. Lorie (Data Base Techniques for Pictorial Applications, 1979)

Grammar Characterization of Flowgraphs. - Jose Luis Becerril; Jose Bondia; Ramón Casajuana; Francisco Valer (IBM J. Res. Dev., 1980)