This earth of ours, past and present

Chicago citation style
Wolfe, Caleb Wroe, 1908-1980. This earth of ours, past and present. [1950]. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/010545171. (Accessed October 19, 2018.)
APA citation style
Wolfe, Caleb Wroe, 1908-1980, ([1950]) This earth of ours, past and present. Retrieved from the Digital Public Library of America, http://catalog.hathitrust.org/Record/010545171
MLA citation style
Wolfe, Caleb Wroe, 1908-1980. Retrieved from the Digital Public Library of America <http://catalog.hathitrust.org/Record/010545171>.
Note: These citations are programmatically generated and may be incomplete.