M. F. Salman, J. O. Ayinla, C. O. Adeniyi, L. Ogundele, and S. . K. Ameen, “Effect of Problem-Solving Instructional Strategy on Senior Secondary School Students’ Attitude towards Mathematics in Ondo, Nigeria”, 5007, vol. 7, no. 1, pp. 1056–1066, Jul. 2012.