Colton's map of Oregon & Washington Territory / issued by the Oregon State Board of Immigration ; prepared by G.W. & C.B. Colton & Co.
MLA
G. W., et al. Colton's Map of Oregon & Washington Territory / Issued by the Oregon State Board of Immigration ; Prepared by G.W. & C.B. Colton & Co. G.W. & C.B. Colton & Co., 0AD. https://collections.library.yale.edu/catalog/15821580.
APA, 6th edition
G. W., Colton, C. B., & C. (0 C.E.). Colton's map of Oregon & Washington Territory / issued by the Oregon State Board of Immigration ; prepared by G.W. & C.B. Colton & Co. [Maps]. G.W. & C.B. Colton & Co., https://collections.library.yale.edu/catalog/15821580.