General geology report. Bulletin G 33, etc Pennsylvania. Bureau of Topographic and Geologic Survey Published: 1965 Total Pages: Get eBook
General Catalogue of Printed Books British Museum. Department of Printed Books Published: 1972 Total Pages: 576 Get eBook
General Catalogue of Printed Books to 1955 British Museum. Dept. of Printed Books Published: 1967 Total Pages: 1230 Get eBook
Bulletin of the United States Geological Survey Geological Survey (U.S.) Published: 1885 Total Pages: 792 Get eBook
General Catalogue of Printed Books British Museum. Dept. of Printed Books Published: 1959 Total Pages: 584 Get eBook
