Círculo y circunferencia[br]LeAnn E. Neel-Romine, Sara Paul and Kathryn G. Shafer (2012). [url=https://app.box.com/s/q98y2mnrsezuubcknltc6md4iwojqfxi][color=#0066cc]Get to Know a Circle[/color][/url]. [i]Mathematics Teaching in the Middle School 18[/i](4), pp. 222-227. doi: [url=http://doi.org/10.5951/mathteacmiddscho.18.4.0222][color=#0066cc]10.5951/mathteacmiddscho.18.4.0222[/color][/url][br]