1. Critical review of the bibilography on unbalanced magnetic pull in dynamoelectric machines;Alexander;Transactions of the American Institute of Electrical Engineers,1918
2. Magnetic pull in machines;Rosenberg;Transactions of the American Institute of Electrical Engineers,1918
3. Quite induction motor;Hildebrand;Transactions of the American Institute of Electrical Engineers,1930
4. The calculation of unbalanced magnetic pull in synchronous and induction motors;Robinson;Electrical Engineering,1943
5. The Practical importance of unbalanced magnetic pull, possibilities of calculating and damping it;Fronhe;Conti Elektro Berichte,1967