%0 Journal Article %A B. I. Stepanov %A Ya. S. Khvashchevskaya %T Absorption spectra with cold light sources %J Doklady Akademii Nauk %D 1957 %P 588-590 %V 116 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1957_116_4_a16/ %G ru %F DAN_1957_116_4_a16