BITTEL, L. R. [., & RAMSEY, J. E. [. (1989). Encyclopedia of professional management (Ed. 2.). Grolier International.

BITTEL, Lester Robert [Ed.], and Jackson E. [Ed.] RAMSEY. Encyclopedia of Professional Management. Ed. 2. Danbury: Grolier International, 1989.

BITTEL, Lester Robert [Ed.], and Jackson E. [Ed.] RAMSEY. Encyclopedia of Professional Management. Ed. 2. Grolier International, 1989.