G. Davis, and M. Mcgowen. proceedings of the Annual Meeting of the 26th Annual Meeting of the International Group for the Psychology of Mathematics Education (PME), 2, page 273-280. Norwich, UK, University of Norwich, (July 2002)
R. Müller, and K. Thoring. Leading Innovation through Design: Proceedings of the DMI 2012 International Research Conference, page 181-192. University of Virginia, (2012)
H. Butler, C. Dwyer, M. Hogan, A. Franco, S. Rivas, C. Saiz, and L. Almeida. Thinking Skills and Creativity, 7 (2):
112-121(2012)New Perspectives on Developing and Assessing Thinking: Selected papers from the 15th International Conference on Thinking.