• Analysis and study of the influence of the geometrical parameters of mini unmanned quad-rotor helicopters to optimise energy savingPenkov, Igor; Aleksandrov, DmitriInternational journal of automotive and mechanical engineering2017 / p. 4730-4746 : ill https://doi.org/10.15282/ijame.14.4.2017.11.0372 https://www.scopus.com/sourceid/21100235622 https://www.scopus.com/record/display.uri?eid=2-s2.0-85044041255&origin=inward&txGid=678846bf84109314a2811eb5ec00328c