supervised.md

@@ -2,7 +2,7 @@
 
 We have developed a supervised machine learning tool called Target Mate (TM). Code for this tool can be found in the CC repository: `tool/targetmate/`.
 
-TM uses CC signatures as features, similar to the use of structural descriptors in structure-activity relationship (SAR) studies.
+TM uses CC signatures as features, similar to the use of structural descriptors in structure-activity relationship (SAR) studies. TM was first presented in [this article](https://docs.google.com/document/d/1vjB-pfvvfhjXCMxrGRiqLdCJaO1P9Q3A0vfn6o4jG_8/edit?ts=5d433c31).
 
 #### Machine-learning problem