| APA | Smart Define. (2016). sullenness thesaurus. Retrieved September 28, 2026, from https://smartdefine.org/sullenness/thesaurus/related |
| Chicago | Smart Define. 2016. "sullenness thesaurus" https://smartdefine.org/sullenness/thesaurus/related (accessed September 28, 2026). |
| Harvard | Smart Define 2016, sullenness thesaurus, Smart Define, viewed 28 September, 2026, <https://smartdefine.org/sullenness/thesaurus/related>. |
| MLA | Smart Define. "sullenness thesaurus" 23 March 2016. Web. 28 September 2026. <https://smartdefine.org/sullenness/thesaurus/related> |