• Intermediate and low radiofrequency electromagnetic field transmission properties in case of common building materials [Online resource]Koppel, Tarmo; Shishkin, Andrei; Toropovs, Nikolajs; Haldre, Heldur; Hussainova, Irina; Mironovs, Viktors; Tint, Piia2016 57th International Scientific Conference on Power and Electrical Engineering of Riga Technical University (RTUCON) : October 13, 14, 2016 : conference proceedings2016 / [6] p. : ill https://doi.org/10.1109/RTUCON.2016.7763144
• Reflection and transmission properties of common construction materials at 2.4 GHz frequencyKoppel, Tarmo; Shishkin, Andrei; Haldre, Heldur; Toropovs, Nikolajs; Vilcane, Inese; Tint, PiiaEnergy procedia2017 / p. 158-165 https://doi.org/10.1016/j.egypro.2017.04.045 https://www.scopus.com/sourceid/17700156736 https://www.scopus.com/record/display.uri?eid=2-s2.0-85020705025&origin=inward&txGid=91b874ceb83a04fab702e29b7a24394e https://www.webofscience.com/wos/woscc/full-record/WOS:000416786300024