diff --git a/Exports-Files.md b/Exports-Files.md
index 5c5ec53..b848530 100644
--- a/Exports-Files.md
+++ b/Exports-Files.md
@@ -74,6 +74,8 @@ For example, `oli.js` includes the following definition:
 
 This will prevent the Compiler from renaming `setMap` internally, allowing the creation of custom controls defining their own `setMap` functions. (The `ol.control.Control.prototype.setMap` function is also exported, making it possible to call it from child implementations.)
 
+http://ol3js.org/ol3/master/examples/custom-controls.html provides an example for creating custom controls.
+
 ## Under the hood
 
 `build/src/internal/src/requireall.js` is used in the `build.py build-all` target to ensure that all source files are passed to the compiler.