• Piccolo-stick and pcb-coil based simple coin validatorReidla, Marko; Märtens, Olev; Land, Raul; Rist, MarekEDERC 2012 : proceedings of the 5th European DSP in Education & Research Conference : 13-14 September 2012, Amsterdam, The Netherlands2012 / p. 81-84 https://ieeexplore.ieee.org/document/6532230