1. Department of Physics and Computer Science, Xavier University of Louisiana, New Orleans, LA 70125, USA
2. Department of Mathematics, State University of New York Cortland, Cortland, NY 13045, USA
3. Department of Mathematical Sciences, Middle Tennessee State University, Murfreesboro, TN 37132, USA
4. Department of Mathematics and Physics, Roger Williams University, Bristol, RI 02809, USA
5. Department of Mathematics, The University of Tampa, Tampa, FL 33606, USA