3Jaffe, Adam B., Manuel Trajtenberg and Michael S. Fogarty, Knowledge Spillovers and Patent Citations: Evidence from A Survey of Inventors. American Economic Review, Papers and Proceedings, pp. 215-218, May 2000.
4Jaffe, Adam B, Manuel Trajtenberg and Michael S Fogarty,Knowledge Spillovers and Patent Citations: Evidence from A Survey of Inventors.American Economic Review, Papersand Proceedings, pp.215-218, May 2000.