| APA | Smart Define. (2011). stiff as a board thesaurus. Retrieved September 29, 2026, from https://smartdefine.org/stiff_as_a_board/thesaurus/synonyms |
| Chicago | Smart Define. 2011. "stiff as a board thesaurus" https://smartdefine.org/stiff_as_a_board/thesaurus/synonyms (accessed September 29, 2026). |
| Harvard | Smart Define 2011, stiff as a board thesaurus, Smart Define, viewed 29 September, 2026, <https://smartdefine.org/stiff_as_a_board/thesaurus/synonyms>. |
| MLA | Smart Define. "stiff as a board thesaurus" 24 May 2011. Web. 29 September 2026. <https://smartdefine.org/stiff_as_a_board/thesaurus/synonyms> |