TY  - SER
AU  - Heinrich,E.WM
ED  - Symposium on industrial minerals of the upper Midwest
TI  - Geologic types of glass-sand deposits and some North American representatives
SN  - 00167606
KW  - Sable substance
KW  - Silice
KW  - Quartzite
KW  - ortho quartzite
KW  - Etats Unis
N1  - <Donation ORSTOM>; bibliogr. p. 613
ER  -