Michael Sipser, Introduction to the Theory of Computation
Αναδρομικές: Part 2
Πολυπλοκότητα: Part 3
link: https://ac.informatik.uni-freiburg.de/teaching/ss_23/tcs_bridging/book/Introduction_to_the_theory_of_computation_by_Michael_Sipser.pdf

Harry R. Lewis, Christos Papadimitriou, Elements of the Theory of Computation
Αναδρομικές: Ch. 4,5
Πολυπλοκότητα: Ch. 6,7
link: https://www.awa2el.net/sites/default/files/nzry_hsbt_ltb_lthny.pdf