WITOS, Franciszek, et al. “Calibration and Laboratory Testing of Computer Measuring System 8AE-PD Dedicated for Analysis of Acoustic Emission Signals Generated by Partial Discharges Within Oil Power Transformers”. Archives of Acoustics, vol. 42, no. 2, Apr. 2017, pp. 297–311, https://doi.org/10.1515/aoa-2017-0032.