Eko, E. E. (1999). Effective writing. Heinemann Educational Books.
Lua i Stíl Chicago (17ú heag.)Eko, Ebele E. Effective Writing. Heinemann Educational Books, 1999.
Lua MLA (9ú heag.)Eko, Ebele E. Effective Writing. Heinemann Educational Books, 1999.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.