00467nam a2200157Ia 4500003000900000008004100009040001600050080001500066100002300081245007100104260005500175300000800230650001500238650004100253650001500294IN-BaIIA211028s9999    xx            000 0 eng d  cIIA Library  a521.9bVAR  aVarnum, William B. 0aDifferential refraction in positional astronomycWilliam B. Varnum  aNew YorkbCarnegie Institution of Washingtonc1922  a50p  aAstrometry  aAstronomy and Astrophysics thesaurus  aRefraction