1. Department of Mathematics and Physics, Colorado State University – Pueblo https://dx.doi.org/6759 2200 Bonforte Lane, Pueblo, CO 81001–4901 USA
2. School of Teacher Education, Florida State University https://dx.doi.org/7823 1114 West Call Street, Tallahassee, FL 32306–4459 USA
3. Independent Scholar 9573 North Sharon Avenue, Fresno, CA 93720 USA