McDonald, James E. Cloudiness over the southwestern United States and its relation to astronomical observing - (Tucson) : University of Arizona. Institute of Atmospheric Physics, 1958 - 67 p. : ilus - Scientific report ; 7 . - Scientific report ; 7 . LCCN: 27972 Subjects--Topical Terms: Meteorología--E.U.A.Nubes.Observaciones meteorológicas. Dewey Class. No.: 551.5724 / M3