X-RAY SHADOWS OF THE DRACO NEBULA : A NEW METHOD TO DETERMINE TOTAL HYDROGEN COLUMN DENSITIESPeter Moritz, S. L. Snowden, R. Egger et al.|Unknown|1998Cited by 0
A new method to determine total hydrogen column densitiesPeter Moritz, R. Egger, A. Wennmacher et al.|Unknown|1998Cited by 0