| APA | Smart Define. (2013). ball pen thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/ball_pen/thesaurus/related |
| Chicago | Smart Define. 2013. "ball pen thesaurus" https://smartdefine.org/ball_pen/thesaurus/related (accessed September 26, 2026). |
| Harvard | Smart Define 2013, ball pen thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/ball_pen/thesaurus/related>. |
| MLA | Smart Define. "ball pen thesaurus" 18 May 2013. Web. 26 September 2026. <https://smartdefine.org/ball_pen/thesaurus/related> |