| APA | Smart Define. (2015). natural philosophy thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/natural_philosophy/thesaurus/narrower |
| Chicago | Smart Define. 2015. "natural philosophy thesaurus" https://smartdefine.org/natural_philosophy/thesaurus/narrower (accessed September 29, 2026). |
| Harvard | Smart Define 2015, natural philosophy thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/natural_philosophy/thesaurus/narrower>. |
| MLA | Smart Define. "natural philosophy thesaurus" 14 April 2015. Web. 29 September 2026. <https://smartdefine.org/natural_philosophy/thesaurus/narrower> |