Added links to REF.md references.

REFS.md

@@ -1,13 +1,16 @@
 Deep Belief Nets
--------
-* "A Fast Learning Algorithm for Deep Belief Nets" Geoffrey Hinton 2006 - Introduces contrastive divergence and DBNs
-* "A Practical Guide to Training Restricted Boltzmann Machines" Geoffrey Hinton 2010 - How to implement DBNs
+----------------
 
-Convolutional Neural Nets:
--------
-* "Handwritten Digit Recognition with a Back-Propagation Network" Yann LeCun 1990 - Introduces CNNs
-* "Notes on Convolutional Neural Networks" Jake Bouvrie 2006 - How to implement CNNs
+* ["A Fast Learning Algorithm for Deep Belief Nets"](http://www.cs.toronto.edu/~hinton/absps/ncfast.pdf) Geoffrey Hinton 2006 - Introduces contrastive divergence and DBNs
+* ["A Practical Guide to Training Restricted Boltzmann Machines"](http://www.cs.toronto.edu/~hinton/absps/guideTR.pdf) Geoffrey Hinton 2010 - How to implement DBNs
+
+Convolutional Neural Nets
+-------------------------
+
+* ["Handwritten Digit Recognition with a Back-Propagation Network"](http://yann.lecun.com/exdb/publis/pdf/lecun-90c.pdf) Yann LeCun 1990 - Introduces CNNs
+* ["Notes on Convolutional Neural Networks"](http://cogprints.org/5869/1/cnn_tutorial.pdf) Jake Bouvrie 2006 - How to implement CNNs
 
 Auto Encoders
--------
-* "Extracting and Composing Robust Features with Denoising Autoencoders" Pascal Vincent 2008 - Introduces the Denoising Autoencoder
+-------------
+
+* ["Extracting and Composing Robust Features with Denoising Autoencoders"](http://www.iro.umontreal.ca/~vincentp/Publications/vincent_icml_2008.pdf) Pascal Vincent 2008 - Introduces the Denoising Autoencoder