APA (7th ed.) Citation

Baker, D. W. (1890). History of the Harvard College Observatory during the period 1840-1890.

Chicago Style (17th ed.) Citation

Baker, Daniel W. History of the Harvard College Observatory During the Period 1840-1890. Cambridge, 1890.

MLA (9th ed.) Citation

Baker, Daniel W. History of the Harvard College Observatory During the Period 1840-1890. 1890.