The brightness of the zenith sky during twilight—Part II
Tài liệu tham khảo
M. W. ChiplonkarProc. Ind. Acad. Sci., A, 1941,14, 70.
F. Link The values are taken from the table in Gruner's article “Neueste Dammerungsforschungen”, inErgebnisse der Kosmischen Physik, 1938,Band 3, 139.
Jean DufayBulletin de l'observatoire de Lyons, 1929,Tome 11, No. 2, 45–50.
Bauer, Danjon and LangevinComptes Rendus, 1924,178, 2115. The values are quoted from Gruner's article referred to above.