Fix URL

readme.rst

@@ -3,9 +3,11 @@ HBMQTT
 
 ``HBMQTT`` is an open source `MQTT`_ client and broker implementation.
 
-Built on top of :mod:`asyncio`, Python's standard asynchronous I/O framework, HBMQTT provides a straightforward API
+Built on top of `asyncio`_, Python's standard asynchronous I/O framework, HBMQTT provides a straightforward API
 based on coroutines, making it easy to write highly concurrent applications.
 
+.. _asyncio: https://docs.python.org/3/library/asyncio.html
+
 Features
 --------
 
@@ -39,6 +41,7 @@ Getting started
 ---------------
 
 hbmqtt is available on `Pypi <https://pypi.python.org/pypi/hbmqtt>`_ and can installed simply using ``pip`` :
+::
 
     $ pip install hbmqtt
 
@@ -46,7 +49,8 @@ Documentation is available on `Read the Docs`_.
 
 Bug reports, patches and suggestions welcome! Just `open an issue`_ or join the `forum`_.
 
-
+.. _MQTT: http://www.mqtt.org
+.. _MQTT 3.1.1: http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html
 .. _Read the Docs: http://hbmqtt.readthedocs.org/
 .. _open an issue: https://github.com/beerfactory/hbmqtt/issues/new
 .. _forum: http://forum.beerfactory.org/c/hbmqtt