V. Augutis, D. Gailius, R. Misevicius, and M. Juraska, “Measurements and Processing of Signals used in a Cab Signaling System”, ELEKTRON ELEKTROTECH, vol. 18, no. 9, pp. 27–30, Nov. 2012, doi: 10.5755/j01.eee.18.9.2800.