TY  - BOOK
AU  - Cottrell,K.W.
TI  - Gypsum in 1921
T2  - Mineral Resources of the United States, 1921-Part II
U1  - 661 
PY  - 1922///
CY  - Washington, D.C.
PB  - Government Printing Office
KW  - MINERIA
KW  - YESO
N1  - Impreso
ER  -