Drucker, P. F. (1995). Managing in a time of great change. Truman Alley Books.
Lua i Stíl Chicago (17ú heag.)Drucker, Peter Ferdinand. Managing in a Time of Great Change. New York: Truman Alley Books, 1995.
Lua MLA (9ú heag.)Drucker, Peter Ferdinand. Managing in a Time of Great Change. Truman Alley Books, 1995.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.