APA
Oppenheim A.V & Willsky A.S, .Signals and Systems. New Delhi: PHI.
Chicago
Oppenheim A.V & Willsky A.S, .Signals and Systems. New Delhi: PHI.
Harvard
Oppenheim A.V & Willsky A.S, .Signals and Systems. New Delhi: PHI.
MLA
Oppenheim A.V & Willsky A.S, .New Delhi: PHI. .