Added dates and authors to economics section

economics/README.md

@@ -1,7 +1,7 @@
-# Economics 
+# Economics
 
 ## Auctions and Bidding
 
-* [Auctions and bidding: A guide for computer scientists](http://www.sci.brooklyn.cuny.edu/~parsons/projects/mech-design/publications/bluffers-final.pdf) by Simon Parsons
+* [Auctions and bidding: A guide for computer scientists (2011)](http://www.sci.brooklyn.cuny.edu/~parsons/projects/mech-design/publications/bluffers-final.pdf) by S. Parsons, J. Rodriguez-Aguilar, M. Klein
 
-* [Optimal Bidding in Online Auctions] (http://www.mit.edu/~dbertsim/papers/Revenue%20Management/Optimal%20Bidding%20in%20Online%20Auctions.pdf) by Dimitris Bertsimas, Jerey Hawkinsy, Georgia Perakis 
+* [Optimal Bidding in Online Auctions (2001)] (http://www.mit.edu/~dbertsim/papers/Revenue%20Management/Optimal%20Bidding%20in%20Online%20Auctions.pdf) by Dimitris Bertsimas, Jerey Hawkinsy, Georgia Perakis