1. Computer Relaying. IEEE Tutorial Course, 79 EH0148-7-PWR.
2. Recent Development in Digital Computer Based Protection and Control in Electric Power Sub-station;Phadke,1980
3. Harmonic-Current-Restrained Relays for Differential Protection;Kennedy;AIEE Trans.,1948
4. An Improved Transformer Differential Relay;Mathews;AIEE Trans.,1954
5. A Transformer Differential Relay with Second Harmonic Restraint;Sharp;AIEE Trans.,1958