Erol, Mustafa, Kadir HocaoÄŸlu, and Åžeyda Kaya. 2020. “easurement of pring onstants of arious pring-ass ystems by sing martphones: eaching roposal”. omentum: hysics ducation ournal 4 (1):1-10. https://doi.org/10.21067/mpej.v4i1.4150.