@article{articlea4db11e1,
title   = {A new algorithm to estimate sky condition based on 5 minutes-averaged values of clearness index and relative optical air mass},
author = {Assuncao, H F and Escobedo, J F and Oliveira, Amauri Pereira de},
year = {2007},
doi = {10.1007/s00704-006-0283-z},
journal   = {Theoretical and Applied Climatology}
}