Perry, Christine A., and Vivian F. Cyrus. “Mathematical Explorations: Visualizing Algebraic Rules for the Nth Term”. Mathematics Teaching in the Middle School, vol. 19, no. 7, 2014, pp. 443-51, https://doi.org/10.5951/mathteacmiddscho.19.7.0443.
Perry, C. A., & Cyrus, V. F. (2014). Mathematical Explorations: Visualizing Algebraic Rules for the nth Term. Mathematics Teaching in the Middle School, 19(7), 443-451. https://doi.org/10.5951/mathteacmiddscho.19.7.0443
Perry CA, Cyrus VF. Mathematical Explorations: Visualizing Algebraic Rules for the nth Term. Mathematics Teaching in the Middle School. 2014;19(7):443-51.