Bleech, J. M., & Mutechler, D. G. (1997). The art of effective selling. Excel Books.
Chicago Style aipamenaBleech, James M., and David G. Mutechler. The Art of Effective Selling. New Delhi: Excel Books, 1997.
MLA aipamenaBleech, James M., and David G. Mutechler. The Art of Effective Selling. Excel Books, 1997.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.