| APA | Smart Define. (2013). point of periapsis thesaurus. Retrieved September 25, 2026, from https://smartdefine.org/point_of_periapsis/thesaurus/narrower |
| Chicago | Smart Define. 2013. "point of periapsis thesaurus" https://smartdefine.org/point_of_periapsis/thesaurus/narrower (accessed September 25, 2026). |
| Harvard | Smart Define 2013, point of periapsis thesaurus, Smart Define, viewed 25 September, 2026, <https://smartdefine.org/point_of_periapsis/thesaurus/narrower>. |
| MLA | Smart Define. "point of periapsis thesaurus" 18 May 2013. Web. 25 September 2026. <https://smartdefine.org/point_of_periapsis/thesaurus/narrower> |