Whenever possible, purchase a physical copy or an authorized e-book. Having a physical reference book is highly beneficial for the intensive calculations and multi-page phasor diagrams required in electrical machine analysis.

"Electrical Machines 2" by J.B. Gupta is a comprehensive textbook that covers the principles and applications of electrical machines. The book is designed for undergraduate students of electrical engineering and is a sequel to "Electrical Machines 1", which covers the basics of electrical machines.

The theoretical foundation explaining why single-phase induction motors are not self-starting.