VELYKOCHYY, V. ., DEREVJANKO, S. . and VYCHIVSKYI, P. . (2019) “TO THE 80TH ANNIVERSARY OF PROFESSOR KALAKURA YA.S. AND THE 55TH ANNIVERSARY OF HIS SCIENTIFIC AND PEDAGOGICAL ACTIVITY”, Journal of Vasyl Stefanyk Precarpathian National University, 6(2), pp. 133–137. doi: 10.15330/jpnu.6.2.133-137.