When researching a site, try searching the site name first. This will retrieve full-length books on the site.
E.g. Lascaux; Qustul; Tikal; Çatalhöyük (diacritics not required)
Next, try searching for the broader geographic region or time period for which your site is important. There may be a chapter, or smaller portions of the book, that address your site in a broader context.
E.g. Turkey AND Neolithic; Maya AND Antiquities
If your site or topic is very narrow, and not well represented in book-length studies, try searching for scholarly journal articles in a database such as AnthropologyPlus, HRAF, or JSTOR.