Horowitz, B. (2014). Hard things about hard things: Building business when there are no easy answers. Harper Business.
Chicago Style aipamenaHorowitz, Ben. Hard Things About Hard Things: Building Business When There Are No Easy Answers. New York: Harper Business, 2014.
MLA aipamenaHorowitz, Ben. Hard Things About Hard Things: Building Business When There Are No Easy Answers. Harper Business, 2014.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.