Two pick-axes

Chicago citation style
Two pick-axes. 1991-1992. Retrieved from the Digital Public Library of America, http://ark.digitalcommonwealth.org/ark:/50959/zk51x143f. (Accessed June 20, 2018.)
APA citation style
(1991-1992) Two pick-axes. Retrieved from the Digital Public Library of America, http://ark.digitalcommonwealth.org/ark:/50959/zk51x143f
MLA citation style
Retrieved from the Digital Public Library of America <http://ark.digitalcommonwealth.org/ark:/50959/zk51x143f>.
Note: These citations are programmatically generated and may be incomplete.