Lugton, R. C. (1970). English as a second language: Current issues. Center for Curriculum Development.
Lua i Stíl Chicago (17ú heag.)Lugton, Robert C. English as a Second Language: Current Issues. Philadelphia, Pa: Center for Curriculum Development, 1970.
Lua MLA (9ú heag.)Lugton, Robert C. English as a Second Language: Current Issues. Center for Curriculum Development, 1970.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.