@misc{indiciaea8bbf043886c, title = {Preliminary geologic map of the Hayward Quadrangle, Alameda and Contra Costa counties, California}, author = {T. W. Dibblee}, year = {1980}, doi = {10.3133/ofr80540}, url = {https://pubs.usgs.gov/publication/ofr80540}, note = {Source identifier: ofr80540} }