1. Ainsworth, S. E. (1999). Designing Effective Multi-representational Learning Environments (report number 58), ESRC Centre for Research in Development, Instruction and Training, University of Nottingham, technical.
2. Alibali, M. W., Kita, S., & Young, A. J. (2000). Gesture and the process of speech production: we think, therefore we gesture. Language and Cognitive Processes, 15, 593–613. doi: 10.1080/016909600750040571 .
3. Bartolini Bussi, M., Chiappini, G., Paola, D., Reggiani, M., & Robutti, O. (2004). Teaching and learning mathematics with tools. In L. Cannizzaro, A. Pesci, & O. Robutti (Eds.), Research and Teacher Training in Mathematics Education in Italy: 2000–2003 (pp. 138–169). Milano: Ghisetti e Corvi Editori.
4. Beichner, R. (1994). Testing student interpretation of kinematics graphs. American Journal of Physics, 62, 750–762. doi: 10.1119/1.17449 .
5. Borba, M. C., & Confrey, J. (1996). A students’ construction of transformations of functions in a multi-representational environment. Educational Studies in Mathematics, 31(3), 319–337. doi: 10.1007/BF00376325 .