00536nam a2200169Ia 4500003000900000008004100009020001800050040001600068080001500084100001900099245009100118260004800209300001500257650002800272650004100300650002500341IN-BaIIA211028s9999    xx            000 0 eng d  a0-521-33907-3  cIIA Library  a520.8bWAL  aWalker, Gordon 0aAstronomical observationscGordon Walker                                                aCambridgebCambridge University Pressc1987  axii, 347p.  aAstronomical techniques  aAstronomy and astrophysics thesaurus  aOptical observations