| APA | Smart Define. (2015). doorsill thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/doorsill/thesaurus/narrower |
| Chicago | Smart Define. 2015. "doorsill thesaurus" https://smartdefine.org/doorsill/thesaurus/narrower (accessed September 26, 2026). |
| Harvard | Smart Define 2015, doorsill thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/doorsill/thesaurus/narrower>. |
| MLA | Smart Define. "doorsill thesaurus" 10 April 2015. Web. 26 September 2026. <https://smartdefine.org/doorsill/thesaurus/narrower> |