@book{1234,
	author = {Helfrick, Albert D. and Cooper, William David.},
	title = {Modern Electronic Instrumentation and Measurement Techniques },
	publisher = {Prentice Hall,},
	year = {2005.},
	address = {Delhi :},
	url = {https://books.google.com.pk/books?id=9qM3YgEACAAJ&dq=Modern+Electronic+Instrumentation+and+Measurement+Techniques&hl=en&sa=X&redir_esc=y}
}