| APA | Smart Define. (2016). sullenly thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/sullenly/thesaurus/synonyms |
| Chicago | Smart Define. 2016. "sullenly thesaurus" https://smartdefine.org/sullenly/thesaurus/synonyms (accessed September 24, 2026). |
| Harvard | Smart Define 2016, sullenly thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/sullenly/thesaurus/synonyms>. |
| MLA | Smart Define. "sullenly thesaurus" 24 March 2016. Web. 24 September 2026. <https://smartdefine.org/sullenly/thesaurus/synonyms> |