If it refers to a specific book, short story, or film (e.g., a telenovela or movie with that title), I’d need the author/director and year.

Paper analyzing “hombres de piel dura” as a Latin American or Spanish masculinity archetype (emotional hardness, resilience, machismo).

I can provide a blank research paper structure (title, abstract, introduction, methods, findings, conclusion, references) for you to fill in with content from the source you have.

To proceed, could you clarify which angle you need?

Analysis of how the phrase is used in online communities (like ok.ru’s Spanish-speaking groups), though again I cannot scrape that site.