^ (2013). Digital Learning : Strengthening and Assessing 21st Century Skills, Grades 5-8ECampus. ISBN 9781118002339 (revised Jan 2024)
^Serim, Ferdi (2015). Digital Learning : Strengthening and Assessing 21st Century Skills, Grades 5-8, Jossey-Bass. BiggerBooks. ISBN 9781118002339 (revised Nov 2023)