Cite

S. P. Langley, Secretary of the Smithsonian Institution, to Mrs. Harriet Parker

MLA

Parker, Peter, 1804-1888. S. P. Langley, Secretary of the Smithsonian Institution, to Mrs. Harriet Parker. 1888 January 13. https://collections.library.yale.edu/catalog/16808604.

APA, 6th edition

Parker, Peter, 1804-1888. (1888 January 13)[S. P. Langley, Secretary of the Smithsonian Institution, to Mrs. Harriet Parker]. https://collections.library.yale.edu/catalog/16808604.