• Slip control upgrades for light-rail electric traction drivesLehtla, Madis; Hõimoja, HardiEPE-PEMC 2008 : 2008 13th International Power Electronics and Motion Control Conference : 1-3 September 2008, Poznan, Poland : abstracts2008 / p. 61 https://ieeexplore.ieee.org/document/4635492