Statistical correlation between hourly and daily values of solar radiation on horizontal surface at sea level in the Italian climate U. Amato, B. Bartoli, B. Coluzzi, V. Cuomo, C. Serio et P. SilvestriniRev. Phys. Appl. (Paris), 21 3 (1986) 219-227DOI: https://doi.org/10.1051/rphysap:01986002103021900