| APA | Smart Define. (2015). old duffer thesaurus. Retrieved September 21, 2026, from https://smartdefine.org/old_duffer/thesaurus/synonyms |
| Chicago | Smart Define. 2015. "old duffer thesaurus" https://smartdefine.org/old_duffer/thesaurus/synonyms (accessed September 21, 2026). |
| Harvard | Smart Define 2015, old duffer thesaurus, Smart Define, viewed 21 September, 2026, <https://smartdefine.org/old_duffer/thesaurus/synonyms>. |
| MLA | Smart Define. "old duffer thesaurus" 14 April 2015. Web. 21 September 2026. <https://smartdefine.org/old_duffer/thesaurus/synonyms> |