This is trolling, but as most of the HN comments here mention the dragon book and a careless reader may get the same impression, let me reply seriously anyway, and point out that the Turing award is not for that: https://awards.acm.org/about/2020-turing

It is for their pioneering research work in algorithms and theory related to compilers (some of which indeed went into some of their books later). Also, even if you consider only books, they wrote nine books, and neither of the two mentioned as most influential is "the dragon book". The first mentioned is the book by Aho, Hopcraft and Ullman: Design and Analysis of Computer Algorithms (1974)

> a classic in the field and was one of the most cited books in computer science research for more than a decade. It became the standard textbook for algorithms courses throughout the world when computer science was still an emerging field.

This predates other major algorithms textbooks like say Kleinberg and Tardos (2005), Skiena (1st ed 1997), CLRS (1st ed 1990), or Sedgewick (1st ed 1983). Easily the standard textbook for more than a decade (and still used in some universities; it's still in print in some countries).

> Principles of Compiler Design (1977)

This is the "green dragon book", not to be confused with Compilers: Principles, Techniques, and Tools (1986, 2nd ed 2006) aka the "red dragon book" and the one people usually mean by "dragon book". This book is not even mentioned in the award citation. (Their automata book was widely used too.)

So the idea that the award was given solely or even primarily for the dragon book seems entirely inaccurate. The Wikipedia pages on Aho and Ullman give some idea of their work: indexed grammars, nested-stack automata, egrep, fgrep / Aho-Corasick algorithm, the algorithms that went into yacc and lex, AWK (Aho), and "one of the founders of the field of database theory" (Ullman).

[Edit: Shortened my very long comment.]