diff --git a/README.rst b/README.rst
index 7254f57..bfbaef5 100644
--- a/README.rst
+++ b/README.rst
@@ -44,3 +44,6 @@ To establish a consistent code quality, please check your code using
 `PHP CodeSniffer`_ against `PSR2 standard`_
 using ``./vendor/bin/phpcs -p --standard=PSR2 --ignore=vendor .``.
 
+.. _`design patterns`: http://en.wikipedia.org/wiki/Software_design_pattern
+.. _`PHP CodeSniffer`: https://github.com/squizlabs/PHP_CodeSniffer
+.. _`PSR2 standard`: https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md