[two_auctions] Add exercises and further reading

lectures/_static/quant-econ.bib

@@ -3055,6 +3055,52 @@ @article{Sargent1979
   pages   = {133--143}
 }
 
+@book{Krishna2009,
+  author    = {Krishna, Vijay},
+  title     = {Auction Theory},
+  edition   = {2nd},
+  publisher = {Academic Press},
+  address   = {San Diego},
+  year      = {2009}
+}
+
+@article{RileySamuelson1981,
+  author  = {Riley, John G. and Samuelson, William F.},
+  title   = {Optimal Auctions},
+  journal = {American Economic Review},
+  volume  = {71},
+  number  = {3},
+  pages   = {381--392},
+  year    = {1981}
+}
+
+@article{Klemperer1999,
+  author  = {Klemperer, Paul},
+  title   = {Auction Theory: A Guide to the Literature},
+  journal = {Journal of Economic Surveys},
+  volume  = {13},
+  number  = {3},
+  pages   = {227--286},
+  year    = {1999}
+}
+
+@book{Milgrom2004,
+  author    = {Milgrom, Paul},
+  title     = {Putting Auction Theory to Work},
+  publisher = {Cambridge University Press},
+  address   = {Cambridge},
+  year      = {2004}
+}
+
+@book{DavidNagaraja2003,
+  author    = {David, Herbert A. and Nagaraja, Haikady N.},
+  title     = {Order Statistics},
+  edition   = {3rd},
+  publisher = {Wiley},
+  address   = {Hoboken, NJ},
+  year      = {2003}
+}
+
 @book{Sargent1987,
   author    = {Sargent, Thomas J},
   edition   = {2nd},