Tasman, F. 2021. Increasing the Ability of Critical and Creative Thinking of Mathematics Teachers of West Sumatra Senior High Schools through Mathematics Learning Design with Geogebra. Pelita Eksakta. 4, 1 (Mar. 2021), 31-36. DOI:https://doi.org/10.24036/pelitaeksakta/vol4-iss1/140.