Grigoryan, D. ON THE UNIQUENESS OF $ \beta\delta $-NORMAL FORM OF TYPED $ \lambda $-TERMS FOR THE CANONICAL NOTION OF $ \delta $-REDUCTION. Proc. YSU A: Phys. Math. Sci. 2019, 53 (1 (248), 37-46. https://doi.org/10.46991/PYSU:A/2019.53.1.037.