Sydorov, M., Salnikova, S., Savelyev, Y., & Oliinyk, O. (2020). Modified SERVPERF and Normalized SERVQUAL Models in Estimation of Service Quality in Higher Educational Institutes. Sociological Studios, 1(16), 29-39. https://doi.org/10.29038/2306-3971-2020-01-29-39