Bittel, L. R. (1976). Improving supervisory performance. Mc Graw-Hill.
Chicago Style aipamenaBittel, Lester R. Improving Supervisory Performance. Auckland: Mc Graw-Hill, 1976.
MLA aipamenaBittel, Lester R. Improving Supervisory Performance. Mc Graw-Hill, 1976.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.