1. Lesk M http://www.lesk.com/mlesk/ksg97/ksg.html 2010
2. Lyman P Varian HR http://www.sims.berkeley.edu/how-much-info http://www.sims.berkeley.edu/how-much-info-2003 2010
3. Bohn R Short J http://hmi.ucsd.edu/pdf/HMI_2009_ConsumerReport_Dec9_2009.pdf 2010
4. Data integration