A Graphical Method of Drawing Iso-lux Curve on Plane Surface
圓等燭圖から等照曲線を求める固式法

Kiyosi Hisano
1934 Journal of the Illuminating Engineering Institute of Japan  
doi:10.2150/jieij1917.18.8_25 fatcat:b3dwfheq5fhwfdffc2kw26x3ri