Holtz-Eakin, Douglas and S. Rosen, Harvey (2004) (E-BOOK): PUBLIC POLICY AND THE ECONOMICS OF ENTERPRENEURSHIP. Massachusetts Institute of Technology. ISBN 0-262-08329-9
Schultz, David (2004) (E-BOOK): ENCYCLOPEDIA OF PUBLIC ADMINISTRATION & PUBLIC POLICY. David Schultz. ISBN 0-8160-4799-5