http://www.med-ed-online.org/resources/PBL_Guide/PBL%20BOOKLET.pdf
http://wikieducator.org/Problem_based_learning
PBL (book chapter)
Problem based learning (BMJ, 2003)
Problems Everywhere? Strengths and Challenges of a Problem-Based Learning Approach in European Studies
The Implementation of Case-Based Learning - Shaping the Pedagogy in Ambulance Education
(Australasian Journal of Paramedicine, 2012)