Sičiūnienė, Viktorija, and Janina Dargytė. “Learning Geometry in Pro-Gymnasium: Achievements and Challenges”. Lietuvos matematikos rinkinys 53, no. B (December 20, 2012): 231–236. Accessed October 27, 2025. https://test.zurnalai.vu.lt/LMR/article/view/17133.