MLA

California. Laws, etc. 1865, California. Legislature, Nagel, L. (Louis), United States. Constitution. 1865. Constitutional amendment abolishing slavery. In Legislature of California, Sixteenth session, 1865 & 1866 .... 1866. https://collections.library.yale.edu/catalog/10604534.

APA, 6th edition

California. Laws, etc. 1865, & California. Legislature, & Nagel, L. (Louis), & United States. Constitution. 1865. (1866)[Constitutional amendment abolishing slavery. In Legislature of California, Sixteenth session, 1865 & 1866 ...]. https://collections.library.yale.edu/catalog/10604534.