Narkevičienė, Bronė, Laima Papreckienė, and Vilija Dabrišienė. “Research Problems in Prof. J. Matulionis Competition of Young Mathematicians”. Lietuvos matematikos rinkinys 42, no. spec. (December 20, 2002): 411–416. Accessed October 28, 2025. https://test.zurnalai.vu.lt/LMR/article/view/32945.