Arola, ?A., Schuster, ?G., Myhre, ?G., Kazadzis, ?S., Dey, ?S., and Tripathi, ?S.?N.: Inferring absorbing organic carbon content from AERONET data, Atmospheric Chemistry and Physics Vol 11 p.215-225 Doi: 10.5194/acp-11-215-2011, 2011