1. S. A. Alyab’ev, E. V. Gorchakov, S. I. Osipov, E. E. Ridel’, and V. N. Khlebnikov, Design and Repair of DC Locomotives [in Russian], Transport, Moscow (1977).
2. E. A. Barbashin, Introduction to the Theory of Stability, Wolters-Noordhoff, Groningen (1970).
3. K. I. Shenfer, Dynamos and DC Motors [in Russian], ONTI, Moscow–Leningrad (1937).
4. H.-L. Choi, Y.-S. Shin, and J.-T. Lim, “Control of nonlinear singularly perturbed systems using feedback linearisation,” IEE Proc.-Control Theory Appl., 152, No. 1, 91–94 (2005).
5. Y. Ikeda, D. D. Ohta, and D. D. Ŝiljak, “Parametric stability,” in: The Ohio State University Joint Conference: (Proceedings of the Univesitá di Genova), Birkhäuser, Boston, Basel, Berlin (1991), pp. 1–20.