APA

Sehgal e. a., . (1972). Modern physics. : Sultan Chand & Sons, New Delhi.

Chicago

Sehgal et al, . 1972. Modern physics. : Sultan Chand & Sons, New Delhi.

Harvard

Sehgal e. a., . (1972). Modern physics. : Sultan Chand & Sons, New Delhi.

MLA

Sehgal et al, . Modern physics. : Sultan Chand & Sons, New Delhi. 1972.