Nieścioruk, Michalina Weronika, et al. “NORMAL SERUM VITAMIN B12 LEVELS IN SYMPTOMATIC PATIENTS: DIAGNOSTIC VALUE OF METHYLMALONIC ACID AND HOMOCYSTEINE IN FUNCTIONAL DEFICIENCY”. International Journal of Innovative Technologies in Social Science, vol. 3, no. 2(50), June 2026, https://doi.org/10.31435/ijitss.2(50).2026.5587.