Petr Doktor และ Martin Goerlich. (2014) Economic aspects of intellectual property protection. Stamford International University:ม.ป.ท.Petr Doktor และ Martin Goerlich. 2014. Economic aspects of intellectual property protection. ม.ป.ท.:Stamford International University;Petr Doktor และ Martin Goerlich. Economic aspects of intellectual property protection. ม.ป.ท.:Stamford International University, 2014. Print.