@book{7683,
	author = {Diagram group},
	title = {comparisons},
	publisher = {ST. Martin's Press , },
	year = {1980 .},
	address = {New York :},
	url = {https://books.google.com.pk/books?id=hChjD0JYcPcC&dq=0312154844&hl=en&sa=X&ved=2ahUKEwjQ0bHMjPf0AhUNfMAKHdx-AhMQ6AF6BAgHEAE}
}