HPP-64-1 DENDRAL-64-A system for computer construction, enumeration and notation of organic molecules as three structures and cyclic graphs. Interim report to the National Aeronautics and Space Administration, December 15, (1964).

DENDRAL is considered the first expert system because it automated the decision-making process and problem-solving behavior of organic chemists. The project consisted of research on two main programs, Heuristic Dendral and Meta-Dendral,^[4] and several sub-programs. It was written in Lisp (programming language). Digital facsimile from the National Library of Medicine at this link.