@article {Kasten89,
	title = {Revised optical air mass tables and approximation formula},
	journal = {Applied Optics},
	volume = {28},
	number = {22},
	year = {1989},
	note = {<br />},
	month = {11/1989},
	pages = {4735{\textendash}4738},
	publisher = {OSA},
	doi = {10.1364/AO.28.004735},
	url = {http://ao.osa.org/abstract.cfm?URI=ao-28-22-4735},
	author = {Fritz Kasten and Andrew T. Young}
}
