Torben Ægidius Mogensen's "Basics of Compiler Design, Chapter 3: Syntax Analysis"
Read subsections 3.4 - 3.6. The functions of a parser include: building an internal representation of the derivation tree and related parser information, and resolving ambiguities of the language pertaining to the input string of tokens.
Click http://web.archive.org/web/20120915222417/http://www.diku.dk/hjemmesider/ansatte/torbenm/Basics/basics_lulu2.pdf link to open resource.