1. Harmonic-current-restrained relays for differential protection;Kennedy;AIEE Trans.,1938
2. M.S. Sachdev, (co-ordinator), Microprocessor relays and protection system, IEEE Tutorial Course Text, Publication No. 88EH0269-1-PWR, 1984.
3. On-line identification of magnetizing inrush and internal faults in three-phase transformers;Sidhu;IEEE Trans. Power Deliv.,1992
4. Power differential method for discrimination between fault and magnetizing inrush current in transformers;Yabe;IEEE Trans. Power Deliv.,1997
5. R.J. Elliott, L. Aggoun, J.B. Moore, Hidden Markov Models, Springer, New York.