text: 14. Uncertain reasoning: Russell & Norvig (2021, chpt. 12–18), Poole, Mackworth & Goebel 
  
  (1998, pp. 345–395), Luger & Stubblefield (2004, pp. 333–381), Nilsson (1998, chpt. 7–12) 
  15. Intractability and efficiency and the combinatorial explosion: Russell & Norvig (2021, p. 21) 
  16. Psychological evidence of the prevalence of sub-symbolic reasoning and knowledge: 
  
  Kahneman (2011), Dreyfus & Dreyfus (1986), Wason & Shapiro (1966), Kahneman, Slovic 
  & Tversky (1982) 
  
  17. Knowledge representation and knowledge engineering: Russell & Norvig (2021, chpt. 10), 
  Poole, Mackworth & Goebel (1998, pp. 23–46, 69–81, 169–233, 235–277, 281–298, 319– 
  345), Luger & Stubblefield (2004, pp. 227–243), Nilsson (1998, chpt. 17.1–17.4, 18) 
  
  18. Smoliar & Zhang (1994). 
  19. Neumann & Möller (2008). 
  20. Kuperman, Reichley & Bailey (2006). 