| APA | Smart Define. (2015). hitherto thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/hitherto/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "hitherto thesaurus" https://smartdefine.org/hitherto/thesaurus/synonyms (accessed September 26, 2026). |
| Harvard | Smart Define 2015, hitherto thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/hitherto/thesaurus/synonyms>. |
| MLA | Smart Define. "hitherto thesaurus" 14 April 2015. Web. 26 September 2026. <https://smartdefine.org/hitherto/thesaurus/synonyms> |