Railroad and county map of Virginia, W. Virginia, Maryland and Delaware.
MLA
Railroad and County Map of Virginia, W. Virginia, Maryland and Delaware. 0AD. https://collections.library.yale.edu/catalog/15603970.
APA, 6th edition
Railroad and county map of Virginia, W. Virginia, Maryland and Delaware. (0 C.E.). [Maps]. https://collections.library.yale.edu/catalog/15603970.