Erduran Avcı, Dilek, and Emine Selcen Darçın. “Investigation of Eight Grade Students’ Knowledge Level about Global Environmental Problems”. International Journal of Physics and Chemistry Education 1, no. 2 (May 21, 2009): 93–98. Accessed July 15, 2025. https://www.ijpce.org/index.php/IJPCE/article/view/10.