@book{1610,
	author = {Hulley, Stephen B.},
	title = {Designing Clinical Research/},
	publisher = {LWW},
	year = {2007.},
	address = {Philadelphia: },
	edition = {3rd ed.},
	url = {https://books.google.com.pk/books?id=L3GQoFQdJ-MC&printsec=frontcover&dq=9780781782104&hl=en&sa=X&ved=2ahUKEwj6gKHu2fv0AhVNxoUKHTL-A0cQ6AF6BAgDEAI#v=onepage&q&f=false}
}