Puttipat Poonsiripukdeekul และ Martin Goerlich. (2014) The competitive advantage of specialty coffee. Stamford international university:ม.ป.ท.Puttipat Poonsiripukdeekul และ Martin Goerlich. 2014. The competitive advantage of specialty coffee. ม.ป.ท.:Stamford international university;Puttipat Poonsiripukdeekul และ Martin Goerlich. The competitive advantage of specialty coffee. ม.ป.ท.:Stamford international university, 2014. Print.