@book{557,
	author = {Helfrick, Albert D. and Cooper, William David.},
	title = {Modern electronic instrumentation and measurement techniques /},
	publisher = {Prentice Hall of India ;},
	year = {c1990.},
	address = {New Delhi :},
	note = {Rev. ed. of: Electronic instrumentation and measurement techniques / William David Cooper, Albert D. Helfrick. 3rd ed. c1985.}
}