| APA | Smart Define. (-0001). geologic age thesaurus. Retrieved September 24, 2026, from https://smartdefine.org/geologic_age/thesaurus/narrower |
| Chicago | Smart Define. -0001. "geologic age thesaurus" https://smartdefine.org/geologic_age/thesaurus/narrower (accessed September 24, 2026). |
| Harvard | Smart Define -0001, geologic age thesaurus, Smart Define, viewed 24 September, 2026, <https://smartdefine.org/geologic_age/thesaurus/narrower>. |
| MLA | Smart Define. "geologic age thesaurus" 30 November -0001. Web. 24 September 2026. <https://smartdefine.org/geologic_age/thesaurus/narrower> |