@book{12553,
	author = {Held, Gilbert},
	title = {Understanding data communications},
	publisher = {Pearson Education Publisher},
	year = {2013},
	address = {New Delhi},
	edition = {7th},
	url = {https://libgen.is/book/index.php?md5=8FFC2FAB24189CAA324DE37837178B2C}
}