diff --git a/doc/index.md b/doc/index.md
index e7fa1d4d02..431d7c0b4e 100644
--- a/doc/index.md
+++ b/doc/index.md
@@ -6,7 +6,9 @@ In general every use of OpenLayers starts by initializing a map, then adding th
 
 Projections
 -----------
-A {@link ol.Projection} defines which point on earth is represented by a pair of coordinates. Coordinates within OpenLayers can be used in various projections where some common projections are always supported, others can be used via Proj4js.
+A {@link ol.Projection} defines which point on earth is represented by a pair of coordinates.
+Coordinates within OpenLayers can be used in various projections where some common projections are always supported,
+others can be used via [Proj4js](http://trac.osgeo.org/proj4js/).
 
 Maps and Layers
 ---------------
@@ -14,4 +16,5 @@ A map in OpenLayers is essentially a staple of layers that is viewed from the to
 
 Contributing
 ------------
-See CONTRIBUTING.md for instructions on building and tesing OpenLayers. The file does also describe how to commit your changes to OpenLayers.
\ No newline at end of file
+See [CONTRIBUTING.md](https://github.com/openlayers/ol3/blob/master/CONTRIBUTING.md) for instructions
+on building and tesing OpenLayers. The file does also describe how to commit your changes to OpenLayers.