MLA

Wagner, Richard, 1813-1883, Weber, J. J., fl. 1862-1871. Verlags-contract. 1862 December 1. https://collections.library.yale.edu/catalog/2053609.

APA, 6th edition

Wagner, Richard, 1813-1883, & Weber, J. J., fl. 1862-1871. (1862 December 1)[Verlags-contract]. https://collections.library.yale.edu/catalog/2053609.