Drucker Peter F. (2004). Effective Executive: The Definitive Guide to Getting the Right Things Done. HBR ,Harper Business.
Lua i Stíl Chicago (17ú heag.)Drucker Peter F. Effective Executive: The Definitive Guide to Getting the Right Things Done. UK: HBR ,Harper Business, 2004.
Lua MLA (9ú heag.)Drucker Peter F. Effective Executive: The Definitive Guide to Getting the Right Things Done. HBR ,Harper Business, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.