Post route map of Porto Rico : showing post offices with the intermediate distances on mail routes in operation on the 1st of December 1912 / published by order of Postmaster General Frank H. Hitchcock.
MLA
Dept, United States. Post Office. Post Route Map of Porto Rico : Showing Post Offices with the Intermediate Distances on Mail Routes in Operation on the 1st of December 1912 / Published by Order of Postmaster General Frank H. Hitchcock. U.S. Post Office Dept., 1912. https://collections.library.yale.edu/catalog/15821954.
APA, 6th edition
Dept, U. S. P. O. (1912). Post route map of Porto Rico : showing post offices with the intermediate distances on mail routes in operation on the 1st of December 1912 / published by order of Postmaster General Frank H. Hitchcock. [Maps]. U.S. Post Office Dept., https://collections.library.yale.edu/catalog/15821954.
