| APA | Smart Define. (2015). eighty-year-old thesaurus. Retrieved October 2, 2026, from https://smartdefine.org/eighty-year-old/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "eighty-year-old thesaurus" https://smartdefine.org/eighty-year-old/thesaurus/synonyms (accessed October 2, 2026). |
| Harvard | Smart Define 2015, eighty-year-old thesaurus, Smart Define, viewed 2 October, 2026, <https://smartdefine.org/eighty-year-old/thesaurus/synonyms>. |
| MLA | Smart Define. "eighty-year-old thesaurus" 10 April 2015. Web. 2 October 2026. <https://smartdefine.org/eighty-year-old/thesaurus/synonyms> |