Many systemic factors work together to make these materials challenging to find. Here's a sneak peek into the library world to briefly explore some of these factors:
Engineering is often lumped together with science, technology, and math as "STEM". While this is useful in some ways, broadly STEM-focused materials often fail to address challenges and considerations that are unique to engineering.
Library materials are typically grouped by topic area, most often (but not always!) in accordance with either Dewey Decimal or Library of Congress classification. Both of these schemes have known major issues with bias, and are even known to completely erase some topics by providing no organization options for them. This can result in related materials being scattered throughout the collection rather than placed together in a browseable unit on the shelf.
This may seem like a simple fix; however, it's not as easy as putting similar materials together. Grouping "diverse" materials together on the shelf can also serve to other those materials, for example by separating the books about women engineers from the other books about engineers, even if the intention is to make them easier to find.
Library subject headings (controlled terms that indicate what an item is about) are notoriously troublesome, particularly when it comes to representing marginalized and minoritized people. Users are sometimes forced to use terminology that is unfavored, old and outdated, or just plain unhelpful as they try to find relevant materials.
Read about ISU Library efforts to improve subject headings related to indigenous people. Efforts are also ongoing to improve subject headings for books about diverse scientists and engineers, so these items should soon be more findable here at Iowa State.
Librarians, who are most often white women, can be allies or gatekeepers. Equity, diversity, and inclusion have not typically been considerations for librarians purchasing or organizing materials. Even today it is often up to the individual librarian to prioritize purchasing these materials (and undertake the necessary extra labor to identify them in the first place) and to make sure they are findable through library systems and on the shelf. This means there is a great deal of inconsistency from library to library.
Like libraries, the publishing industry is very white. Combined with historical inequities, this has an effect on what ideas (and which voices) are selected for publication at all.
Booksellers and vendors add another layer where marginalized voices and social justice topics can be filtered out. They may only sell materials from traditional publishers, or a limited range of self published materials. Historically, there has been a stigma against self published, independently published, or otherwise "non-scholarly" material in the sciences, even when the author is reputable and has important things to say.
Library vendors in particular avoid self published materials, which means most libraries will never include these materials in their collections... even though self publication is often the only option left to authors belonging to groups that have been marginalized.
Check out the Library Guide and embedded slides from the ISCORE 2021 presentation, Diverse STEM Reading: A Layer Cake of Problems.