[9] D. L. Poole and A. K. Mackworth, Artificial intelligence: Foundations of computational agents, 2nd ed. University of British Columbia; Cambridge University Press, 2017. Available: https://artint.info/
[10] S. A. Cook, “The complexity of theorem-proving procedures,” in Proceedings of the third annual ACM symposium on theory of computing, in Stoc ’71. Shaker Heights, Ohio, USA: Association for Computing Machinery, 1971, pp. 151–158. doi: 10.1145/800157.805047.
Warning. These sources are locked behind corporate paywalls or distributed unethically with DRM encryption and/or surveillance.
[11] R. M. Karp, “Reducibility among combinatorial problems,” in Symposium on the complexity of computer computations, 1972. doi: 10.1007/978-1-4684-2001-2\(_9\).