Open Access
@article{118427,
  author       = {Angell, Frank},
  title        = {{Discrimination of Shades of Gray for Different 
                   Intervals of Time}},
  journal      = {Philosophische Studien},
  year         = 1902,
  volume       = 19,
  pages        = {1-21},
  language     = {en},
  url          = {https://vlp-new.ur.de/records/lit4564}
}
