Gaya APA

Bittel, L, R., Ramsey, J, E. (1985). Encyclopedia of professional management second edition volume 1 (-). United States of Amerika: Grolier International.

Gaya MLA

Bittel, Lester, Robert., Ramsey, Jackson, Eugene. "Encyclopedia of professional management second edition volume 1". - United States of Amerika: Grolier International, 1985. UMUM.