Ellah, B. O., E. E. Achor, and V. Enemarie. “Problem-Solving Skills As Correlates of Attention Span and Working Memory of Low Ability Level Students in Senior Secondary Schools”. Journal of Education and E-Learning Research, Vol. 6, no. 3, Aug. 2019, pp. 135-41, doi:10.20448/journal.509.2019.63.135.141.