Porter, J., & Lacey, P. (2005). Researching learning difficulties: A guide for practitioners. P.C.P. ; SAGE Publications.
Lua i Stíl Chicago (17ú heag.)Porter, Jill, agus Penny Lacey. Researching Learning Difficulties: A Guide for Practitioners. London : Thousand Oaks, CA: P.C.P. ; SAGE Publications, 2005.
Lua MLA (8ú heag.)Porter, Jill, agus Penny Lacey. Researching Learning Difficulties: A Guide for Practitioners. P.C.P. ; SAGE Publications, 2005.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.