Walker, A. (1990). Knowledge systems and Prolog: Developing expert, database, and natural language systems (2nd ed.). Addison-Wesley.
Chicago-viite (17. p.)Walker, Adrian. Knowledge Systems and Prolog: Developing Expert, Database, and Natural Language Systems. 2nd ed. Reading, Mass: Addison-Wesley, 1990.
MLA-viite (9. p.)Walker, Adrian. Knowledge Systems and Prolog: Developing Expert, Database, and Natural Language Systems. 2nd ed. Addison-Wesley, 1990.
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