00403nam a22001457a 4500020001800000082001200018100002400030245003200054260004900086300002300135500004500158700001500203700001600218700002300234  a9780393912104  a520 PAL  aPALEN, Stacy et al.  aUnderstanding Our Universe/  aNew York;bW.W. Norton & Company Inc,c2012.  axxix, 485 p.bill.  aINCLUDES:  Appendix, Glossary and Index.  aKAY, Laurn  aSMITH, Brad  aBLUMENTHAL, George