The initial edition was published in 1976, in German, but the latest version is available online:
https://people.inf.ethz.ch/wirth/CompilerConstruction/Compil...
There are also parser generators like ANTLR (https://en.wikipedia.org/wiki/ANTLR) which take an input not unlike yacc, but generate a LL parser using explicit code, rather than the table driven LALR parsing of yacc.