Travers, A. (1988). Supervision: Techniques and new dimension. Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Travers, Alfred. Supervision: Techniques and New Dimension. New Jersey: Prentice Hall, 1988.
Lua MLA (9ú heag.)Travers, Alfred. Supervision: Techniques and New Dimension. Prentice Hall, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.