1. Backus, J.W.: The syntax and semantics of the proposed international algebraic language of the Zurich ACM-GAMM conference. In: IFIP Congress (1959).
https://dblp.uni-trier.de/db/conf/ifip/ifip1959.html
2. Backus, J.W., et al.: Revised report on the algorithm language ALGOL 60. Commun. ACM 6(1), 1–17 (1963)
3. Berstel, J., Lauve, A., Reutenauer, C., Saliola, F.V.: Combinatorics on Words. Christoffel Words and Repetitions in Words. American Mathematical Society (AMS), Providence (2009)
4. Chang, S., Felleisen, M.: The call-by-need lambda calculus, revisited. In: Seidl [30]
5. Chomsky, N.: Three models for the description of language. IRE Trans. Inf. Theory 2(3), 113–124 (1956)