Astronomy : a textbook for university and college students / Robert H. Baker. Baker, Robert Horace, 1883- Astronomy. QB45 .B15 1946 520 BAA "First published, May 1930 ... Fourth edition, April 1946." "Reference books": p. 449-452. New York : D. Van Nostrand, c1946. c1946. 1946 Text x, 461 p. ; eng