HP-GL
Hewlet-Packard Company (1996) (英語) (PDF). The HP-GL/2 and HP RTL Reference Guide - AHandbook for Program Developers (2nd ed.). Barselora, spain: Addison-Wesley. ISBN 0-201-63325-6. HP Part number: 5961-3526.. http://www.hpmuseum.net/document.php?catfile=213
Hewlet-Packard Company (1997) (英語). The HP-GL/2 and HP RTL Reference Guide - AHandbook for Program Developers (3rd ed.). Reading, Mass.: Addison-Wesley. ISBN 0-201-31014-7. NCID BA37680992.