TY  - BOOK
AU  - Butler,G.M.
TI  - Clays of eastern Colorado,
AV  - QE91 .A4 no.8
PY  - 1915///
CY  - Denver, Col.
PB  - The Smith-Brooks printing company
KW  - Clay
KW  - Colorado
N1  - "Partial list of the sources of data consulted in compiling the descriptions of the Colorado clay-bearing formations": p. 148-149
ER  -