1. Preservice secondary school mathematics teachers' knowledge of trigonometry
2. Blacket, N and Tall, DO. Gender and the versatile learning of trigonometry using computer software. Proceedings of the 15th Conference of the International Group for the Psychology of Mathematics Education. Edited by: Furinghetti. Vol. 1, pp.144–151. Lisbon, Portugal
3. Wenzelbuer, E. The learning of trigonometric functions in a graphical computer environment. Proceedings of the 16th Conference of the International Group for the Psychology of Mathematics Education. Edited by: Geeshin, W and Graham, K. Vol. 3, pp.106–114. Durham, USA
4. Silva, ZL. A geometric–algebraic approximate to the trigonometric functions with the use of super calculators. Proceedings of the 18th Conference of the International Group for the Psychology of Mathematics Education. Edited by: da Ponte, JP and Matos, JF. Vol. 1, pp.71Lisbon, Portugal
5. Lobo da Costa, N and Magina, S. 1998.Making sense of sine and cosine functions through alternative aproaches: Computer and experimental world contexts, Edited by: Oliver, A and Newstead, A. Vol. 2, 224–231. Stellenbosch, South Africa: Proceedings of the 22th Conference of the International Group for the Psychology of Mathematics Education.