TY  - BOOK
AU  - Palen, Stacy 
AU  - Kay Laura
AU  - Smith, Brad 
TI  - Understanding our universe 
SN  - 9780393912104
U1  - 520 
PY  - 2012///
CY  - New York
PB  - W.W.Norton & Company 
KW  - Astronomy & allied science
KW  - (Text book)
ER  -