Apynis, Antanas, and Edmundas Mazėtis. “The Problems of Mathematics Education at Secondary Schools and Gymnasia”. Lietuvos matematikos rinkinys 52, no. proc. LMS (December 15, 2011): 67–71. Accessed November 6, 2025. https://www.zurnalai.vu.lt/LMR/article/view/15376.