| APA | Smart Define. (2011). pleasure-unpleasure principle thesaurus. Retrieved October 1, 2026, from https://smartdefine.org/pleasure-unpleasure_principle/thesaurus/antonyms |
| Chicago | Smart Define. 2011. "pleasure-unpleasure principle thesaurus" https://smartdefine.org/pleasure-unpleasure_principle/thesaurus/antonyms (accessed October 1, 2026). |
| Harvard | Smart Define 2011, pleasure-unpleasure principle thesaurus, Smart Define, viewed 1 October, 2026, <https://smartdefine.org/pleasure-unpleasure_principle/thesaurus/antonyms>. |
| MLA | Smart Define. "pleasure-unpleasure principle thesaurus" 23 May 2011. Web. 1 October 2026. <https://smartdefine.org/pleasure-unpleasure_principle/thesaurus/antonyms> |