| APA | Smart Define. (1970). as hard as nails thesaurus. Retrieved September 26, 2026, from https://smartdefine.org/as_hard_as_nails/thesaurus/synonyms |
| Chicago | Smart Define. 1970. "as hard as nails thesaurus" https://smartdefine.org/as_hard_as_nails/thesaurus/synonyms (accessed September 26, 2026). |
| Harvard | Smart Define 1970, as hard as nails thesaurus, Smart Define, viewed 26 September, 2026, <https://smartdefine.org/as_hard_as_nails/thesaurus/synonyms>. |
| MLA | Smart Define. "as hard as nails thesaurus" 1 January 1970. Web. 26 September 2026. <https://smartdefine.org/as_hard_as_nails/thesaurus/synonyms> |