Subrahmanyam, N., & Lal, B. (1974). A textbook of sound: For B.Sc.(Pass Honours and Subsidiary),Engineering sutdunts of Indian University and IAS Examination. G. Bell and sons Ltd. ; Vikas publishing House.

Subrahmanyam, N., and Brij Lal. A Textbook of Sound: For B.Sc.(Pass Honours and Subsidiary),Engineering Sutdunts of Indian University and IAS Examination. London : New Delhi: G. Bell and sons Ltd. ; Vikas publishing House, 1974.

Subrahmanyam, N., and Brij Lal. A Textbook of Sound: For B.Sc.(Pass Honours and Subsidiary),Engineering Sutdunts of Indian University and IAS Examination. G. Bell and sons Ltd. ; Vikas publishing House, 1974.