1. Patents as a measure of innovative activity;Acs;Kyklos,1989
2. Crowdsourcing as a solution to distant search;Afuah;Academy of Management Review,2012
3. Does IP strategy have to cripple open innovation;Alexy;MIT Sloan Management Review,2009
4. Open versus closed innovation: A model of discovery and divergence;Almirall;Academy of Management Review,2010