The First Duty
MLA
Keppler, Joseph Ferdinand, 1838-1894. The First Duty. 1900 August 8. https://collections.library.yale.edu/catalog/2065807.
APA, 6th edition
Keppler, Joseph Ferdinand, 1838-1894. (1900 August 8)[The First Duty]. https://collections.library.yale.edu/catalog/2065807.