00285nam a2200109Ia 4500008004100000082001500041100001500056245003700071250000800108260004200116300001700158190709s9999    xx            000 0 und d  a514.6 R447  aRietz, H L 0aPlane and spherical trigonometry  a3rd  aNew yorkbThe macmillan companyc1957  axiii,205+20+