Simon Fraser University. Cognitive Science Programme & Levine, R. (1992). Formal grammar: Theory and implementation. Oxford University Press.
Lua i Stíl Chicago (17ú heag.)Simon Fraser University. Cognitive Science Programme agus Robert Levine. Formal Grammar: Theory and Implementation. New York: Oxford University Press, 1992.
Lua MLA (9ú heag.)Simon Fraser University. Cognitive Science Programme agus Robert Levine. Formal Grammar: Theory and Implementation. Oxford University Press, 1992.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.