TY  - BOOK
AU  - Heller,Robert L.
ED  - American Geological Institute.
ED  - National Academy of Sciences (U.S.)
ED  - University of Minnesota, Duluth.
TI  - Geology and earth sciences sourcebook for elementary and secondary schools
AV  - QE41 .A55
U1  - 550.7 
PY  - 1962///]
CY  - New York
PB  - Holt, Rinehart and Winston
KW  - Geology
KW  - Study and teaching
N1  - Held on the Duluth campus of the University of Minnesota
UR  - http://www.archive.org/details/geologyearthscie00amer
UR  - http://www.openlibrary.org/books/OL5850579M
ER  -