Drucker, P. F. (1980). Managing in turbulent times. Harper & Row; Butterworth-Heinemann.
Lua i Stíl Chicago (17ú heag.)Drucker, Peter F. Managing in Turbulent Times. New York ; Oxford: Harper & Row; Butterworth-Heinemann, 1980.
Lua MLA (8ú heag.)Drucker, Peter F. Managing in Turbulent Times. Harper & Row; Butterworth-Heinemann, 1980.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.