| APA | Smart Define. (1970). operation underground railroad thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/operation_underground_railroad/thesaurus/related |
| Chicago | Smart Define. 1970. "operation underground railroad thesaurus" https://smartdefine.org/operation_underground_railroad/thesaurus/related (accessed September 26, 2026). |
| Harvard | Smart Define 1970, operation underground railroad thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/operation_underground_railroad/thesaurus/related>. |
| MLA | Smart Define. "operation underground railroad thesaurus" 1 January 1970. Web. 26 September 2026. <https://smartdefine.org/operation_underground_railroad/thesaurus/related> |