@book{7210,
	author = {Cottrell, Geoff},
	title = {Telescopes},
	publisher = {Oxford University Press},
	year = {2016},
	address = {New York},
	url = {https://libgen.is/book/index.php?md5=EF88702B1980C6A40E70653D85C3B9D1}
}