Coons, Albert (October 1999), "Getting started with symbolic mathematics systems: a productivity tool", Technology Tips, The Mathematics Teacher, 92 (7): 620–622, doi:10.5951/mt.92.7.0620, JSTOR27971125
Coons, Albert (October 1999), "Getting started with symbolic mathematics systems: a productivity tool", Technology Tips, The Mathematics Teacher, 92 (7): 620–622, doi:10.5951/mt.92.7.0620, JSTOR27971125