An atlas of the sunspot spectrum from 470 to 1233 cm⁻¹ (8.1 to 21 [micrometers]) and the photospheric spectrum from 460 to 630 cm⁻¹ (16 to 22 [micrometers])Lloyd Wallace, W. C. Livingston, Peter F. Bernath, National Optical Astronomy Observatories (U.S.) · First published 1994Open the Tome