Swan, M., & Walter, C. How english works: A grammar practice book with answers.
Lua i Stíl Chicago (17ú heag.)Swan, Michael, agus Catherine Walter. How English Works: A Grammar Practice Book with Answers.
Lua MLA (8ú heag.)Swan, Michael, agus Catherine Walter. How English Works: A Grammar Practice Book with Answers.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.