1) R. Finkel, et al.: AL, A Progroming System for Automation, MEMO AIM-243, STAN-CS-74-456, Stanford University (1974)
2) S. Mujtaba and R. Goldman: AL User's Manual, MEMO AIM-323, Stanford University (1979)
3) D. D. Grossman and R. H. Taylor: Interactive Generation of Objects Models with a Manipulator, IEEE Trans. Systems, Man, and Cybernetics, SMC-8, 667/679 (1978)