Barner D, Athanasopoulou A, Chu J, Lewis M, Marchand E, Schneider R, Frank M. A One-Year Classroom-Randomized Trial of Mental Abacus Instruction for First- and Second-Grade Students. J Numer Cogn [Internet]. 2018Jan.30 [cited 2026Jun.2];3(3):Article e5761. Available from: https://jnc.psychopen.eu/index.php/jnc/article/view/5761