Wells, R. A. (1998). Stretch: Explore, explain, persuade. Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Wells, Randall A. Stretch: Explore, Explain, Persuade. Upper Saddle River, N.J: Prentice Hall, 1998.
Lua MLA (9ú heag.)Wells, Randall A. Stretch: Explore, Explain, Persuade. Prentice Hall, 1998.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.