Lutsenko, I., Fomovskaya, O., Serdiuk, O., Baranovskaya, M. and Fomovskyi, V. 2018. Development of test operations of different duration in terms of input for the verification of efficiency formula. Eastern-European Journal of Enterprise Technologies. 5, 4 (95) (Sep. 2018), 14–21. DOI:https://doi.org/10.15587/1729-4061.2018.142212.