[1] RE2 regular expression syntax reference (2016-04-22 00:36:58 +09:00 版) <https://re2.googlecode.com/hg/doc/syntax.html>

[2] google/re2: RE2 is a fast, safe, thread-friendly alternative to backtracking regular expression engines like those used in PCRE, Perl, and Python. It is a C++ library. (2016-04-22 00:37:20 +09:00 版) <https://github.com/google/re2>

[3] Syntax · google/re2 Wiki (2016-04-22 00:37:45 +09:00 版) <https://github.com/google/re2/wiki/Syntax>