DRUCKER , P. (1982). THE EFFACTIVE EXECUTIVE. PAN BOOKS.
Lua i Stíl Chicago (17ú heag.)DRUCKER , P.F. THE EFFACTIVE EXECUTIVE. GREAT BRITAIN: PAN BOOKS, 1982.
Lua MLA (9ú heag.)DRUCKER , P.F. THE EFFACTIVE EXECUTIVE. PAN BOOKS, 1982.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.