1. Labour Markets of the Future: The Challenge to Education Policy Makers, in Recent Trends in Vocational Education and Training;Bengtsson;European Journal of Education,1993
2. European Commission Cedefop ICF International 2014 European Inventory on Validation of Non-formal and Informal Learning 2014. Executive Summary http://libserver.cedefop.europa.eu/vetelib/2014/87250.pdf
3. Validation of Formal, Non-formal and Informal Learning: policy and practices in EU Member States, in: Trends in Lifelong Learning: improving opportunities for adult learning;Colardyn;European Journal of Education,2004