If a perfectly diffuse, perfectly reflecting surface has one foot-candle (one lumen per square foot) of illumination falling on it, its luminance is one foot-Lambert or 1/pi candles per square foot.
J. Chung, C. Gulcehre, K. Cho, and Y. Bengio. (2014)cite arxiv:1412.3555Comment: Presented in NIPS 2014 Deep Learning and Representation Learning Workshop.
M. Keijzer, M. Baptist, V. Babovic, and J. Uthurburu. GECCO 2005: Proceedings of the 2005 conference on
Genetic and evolutionary computation, 2, page 1999--2006. Washington DC, USA, ACM Press, (25-29 June 2005)
M. Keijzer, V. Babovic, C. Ryan, M. O'Neill, and M. Cattolico. Proceedings of the Genetic and Evolutionary
Computation Conference (GECCO-2001), page 42--49. San Francisco, California, USA, Morgan Kaufmann, (7-11 July 2001)