| APA | Smart Define. (2013). hard-heartedness thesaurus. Retrieved September 27, 2026, from https://smartdefine.org/hard-heartedness/thesaurus/antonyms |
| Chicago | Smart Define. 2013. "hard-heartedness thesaurus" https://smartdefine.org/hard-heartedness/thesaurus/antonyms (accessed September 27, 2026). |
| Harvard | Smart Define 2013, hard-heartedness thesaurus, Smart Define, viewed 27 September, 2026, <https://smartdefine.org/hard-heartedness/thesaurus/antonyms>. |
| MLA | Smart Define. "hard-heartedness thesaurus" 4 October 2013. Web. 27 September 2026. <https://smartdefine.org/hard-heartedness/thesaurus/antonyms> |