APA
Helfrick A. D. &. C. W. D., . (1990). Modern electronic instrumentation and measurement techniques. PHI learning pvt. ltd: Delhi.
Chicago
Helfrick Albert D & Cooper William D, . 1990. Modern electronic instrumentation and measurement techniques. PHI learning pvt. ltd: Delhi.
Harvard
Helfrick A. D. &. C. W. D., . (1990). Modern electronic instrumentation and measurement techniques. PHI learning pvt. ltd: Delhi.
MLA
Helfrick Albert D & Cooper William D, . Modern electronic instrumentation and measurement techniques. PHI learning pvt. ltd: Delhi. 1990.