(1978). Motivation Part Ii Harvard Business Review. Harvard Business Review.
Lua i Stíl Chicago (17ú heag.)Motivation Part Ii Harvard Business Review. Harvard Business Review, 1978.
Lua MLA (8ú heag.)Motivation Part Ii Harvard Business Review. Harvard Business Review, 1978.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.