Researchr is a web site for finding, collecting, sharing, and reviewing scientific publications, for researchers by researchers.
Sign up for an account to create a profile with publication list, tag and review your related work, and share bibliographies with your co-authors.
Arnold P. O. S. Vermeeren. What's the problem?: studies on identifying usability problems in user tests. PhD thesis, Delft University of Technology, Netherlands, 2009. [doi]