1. ALSTOM Grid. Network protection & automation guide, edition May 2011, ISBN: 978-0-9568678-0-3
2. G. Ziegler, Numerical Distance Protection: Principles and Applications (Publicis Corporate Publishing, SEIMENS, 2008)
3. Protective Relay Engineers, Fundamentals of distance protection, 61st Annual Conference, 1–3 April 2008, College Station, TX, USA, pp. 1–34 (2008)
4. W.A. Elmore, Protective Relaying Theory and Applications (Marcel Dekker Inc., New York, 2004)
5. B.A. Oza, N.C. Nair, R.P. Mehta, V.H. Makwana, Power System Protection and Switchgear (Tata Mcgraw Hill, New Delhi, India, 2010)