Martynova Olena Application of the theory of fuzzy sets in assessing the economic efficiency and risk of investment projects under conditions of uncertainty / Olena Martynova // Science Journal «Economics and Region». – Poltava: PNTU, 2024. – VOL. (1 (92). – PP. 244-250. – doi:https://doi.org/10.26906/EiR.2024.1(92).3336.