@ARTICLE{Feulner2013a, author = {{Feulner}, G.}, title = "{On the Relation Between Solar Activity and Clear-Sky Terrestrial Irradiance}", journal = {Solar Phys.}, keywords = {Atmospheric extinction, Integrated Sun observations, Solar cycle, observations, Sunspots, statistics}, year = 2013, month = feb, volume = 282, pages = {615-627}, doi = {10.1007/s11207-012-0129-z}, }