NAGRATH I J & KOTHARI D P, . (1989). ELECTRIC MACHINES. : TATA MC GRAW HILL.
NAGRATH I J & KOTHARI D P, . 1989. ELECTRIC MACHINES. : TATA MC GRAW HILL.
NAGRATH I J & KOTHARI D P, . ELECTRIC MACHINES. : TATA MC GRAW HILL. 1989.