| APA | Smart Define. (2013). unfrivolous thesaurus. Retrieved September 22, 2026, from https://smartdefine.org/unfrivolous/thesaurus/synonyms |
| Chicago | Smart Define. 2013. "unfrivolous thesaurus" https://smartdefine.org/unfrivolous/thesaurus/synonyms (accessed September 22, 2026). |
| Harvard | Smart Define 2013, unfrivolous thesaurus, Smart Define, viewed 22 September, 2026, <https://smartdefine.org/unfrivolous/thesaurus/synonyms>. |
| MLA | Smart Define. "unfrivolous thesaurus" 28 June 2013. Web. 22 September 2026. <https://smartdefine.org/unfrivolous/thesaurus/synonyms> |