@article {Planck1901,
title = {Distribution of energy in the spectrum},
journal = {Annalen der Physik},
volume = {4},
year = {1901},
note = {
},
month = {03/1901},
pages = {553-563},
author = {M. Planck}
}
@article {Planck1900,
title = {Distribution of energy in the normal spectrum},
journal = {Verhandlungen der Deutschen Physikalischen Gesellschaft},
volume = {2},
year = {1900},
note = {
},
pages = {237-245},
author = {M. Planck}
}