Ur, P. (1981). Discussions that work. Cambridge University Press.
Lua i Stíl Chicago (17ú heag.)Ur, Penny. Discussions That Work. Cambridge: Cambridge University Press, 1981.
Lua MLA (9ú heag.)Ur, Penny. Discussions That Work. Cambridge University Press, 1981.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.