So they say

Chicago citation style
Smith, Harry Bache (1860-1936), Herbert, Victor (1859-1924). So they say. 1900. Retrieved from the Digital Public Library of America, http://digitalcollections.nypl.org/items/89150863-bb3d-5583-e040-e00a18063e9f. (Accessed December 9, 2018.)
APA citation style
Smith, Harry Bache (1860-1936), Herbert, Victor (1859-1924), (1900) So they say. Retrieved from the Digital Public Library of America, http://digitalcollections.nypl.org/items/89150863-bb3d-5583-e040-e00a18063e9f
MLA citation style
Smith, Harry Bache (1860-1936), Herbert, Victor (1859-1924). Retrieved from the Digital Public Library of America <http://digitalcollections.nypl.org/items/89150863-bb3d-5583-e040-e00a18063e9f>.
Note: These citations are programmatically generated and may be incomplete.