Author,Title,Journal,ISSN,Publisher,Date,Volume,Number,Page,URL,URL(DOI) Kato Takeyoshi and Inoue Takato and Honda Nobuyuki and Koaizawa Kazumasa and Nishino Shinichi and Suzuoki Yasuo,Geographical Extent Feasible for Standard Deviation Calculation using 1/√N Rule regarding Ensemble Average Insolation Fluctuation,IEEJ Transactions on Power and Energy,03854213,The Institute of Electrical Engineers of Japan,2012,132,3,213-219,https://cir.nii.ac.jp/crid/1390282679577831552,https://doi.org/10.1541/ieejpes.132.213