1. E. Bakens, and C. Vries (2001 ) [Portfolios in education. A process of selecting and reflecting]. Leiden University: Master thesis, unpublished manuscript.
2. A Meta-Analysis of Measures of Self-Esteem for Young Children: A Framework for Future Measures
3. M. Droop, and S. Peters (2001 ) The impact of early literacy portfolios on classroom practice: effects on attitudes, reading and writing results and consequences for instruction . Paper presented at the symposium 'Portfolios' of the Conference of the European Association of Learning and Instruction in Fribourg, Switzerland, 30 August 2001.