HMELO-SILVER, C. E., L. LIU, and R. JORDAN. “VISUAL REPRESENTATION OF A MULTIDIMENSIONAL CODING SCHEME FOR UNDERSTANDING TECHNOLOGY-MEDIATED LEARNING ABOUT COMPLEX NATURAL SYSTEMS”. Research and Practice in Technology Enhanced Learning, vol. 4, no. 3, Nov. 2009, pp. 253-80, doi:10.58459/rptel.2009.4253-280.