1. Problem-based Learning: A review of literature on its outcomes and implementation issues;Albanese;Academic Medicine,1993
2. A taxonomy of problem-based learning methods;Barrows;Medical Education,1986
3. Problem-based learning in medicine and beyond: A brief overview;Barrows;New Directions for Teaching and Learning,1996
4. Problem-based learning: Have the expectations been met?;Berkson;Academic Medicine,1993
5. Research Methods in Education;Cohen;(6th Edition). London and New York: Taylor & Francis Group or Routledge,2007