Drucker, P. Management (1st rev. ed.). Harper Collins, New York.
Lua i Stíl Chicago (17ú heag.)Drucker, Peter. Management. 1st rev. ed. Harper Collins, New York.
Lua MLA (9ú heag.)Drucker, Peter. Management. 1st rev. ed. Harper Collins, New York.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.