Cite

Reconnaissance map of Ruby district, Alaska / U.S. Geoogical Survey; Alfred H. Brooks, geologist in charge of division.

MLA

Geological Survey (U.S.). Reconnaissance map of Ruby district, Alaska / U.S. Geoogical Survey; Alfred H. Brooks, geologist in charge of division.. BRBL_00634. 1921. https://collections.library.yale.edu/catalog/15821766.

APA, 6th edition

Geological Survey (U.S.). (["BRBL_00634"])(1921)[Reconnaissance map of Ruby district, Alaska / U.S. Geoogical Survey; Alfred H. Brooks, geologist in charge of division.]. https://collections.library.yale.edu/catalog/15821766.