Nasution, F. S., and E. Surya. “Efforts to Increase Student Learning Results With Cooperative Learning Type Learning Model Think Pair Share on the Cube and Beams Materials in Class VIII SMP Kartika I-1 Medan”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 33, no. 3, June 2017, pp. 280-9, https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7466.