| APA | Smart Define. (2015). national park thesaurus. Retrieved October 1, 2026, from https://smartdefine.org/national_park/thesaurus/related |
| Chicago | Smart Define. 2015. "national park thesaurus" https://smartdefine.org/national_park/thesaurus/related (accessed October 1, 2026). |
| Harvard | Smart Define 2015, national park thesaurus, Smart Define, viewed 1 October, 2026, <https://smartdefine.org/national_park/thesaurus/related>. |
| MLA | Smart Define. "national park thesaurus" 10 April 2015. Web. 1 October 2026. <https://smartdefine.org/national_park/thesaurus/related> |