Georgiev, Tsolo, and Mikho Mikhov. “A Sensorless Speed Control System for DC Motor Drives”. Electrical, Control and Communication Engineering 25, no. 25 (January 1, 2009): 155–158. Accessed November 5, 2024. https://ecce-journals.rtu.lv/ecce/article/view/v10144-009-0033-z.