Since this is the Philosophy Library Guide, we might have more tools than other scholars to think about what this question actually asks. For example, what do we mean by trust? Some older texts might be available via websites, and those would be perfectly trustworthy. They may be run by institutions (colleges, universities, archives, or libraries), like these links directly below. Other sites may not be as clear. See the infographic below to the left for a handy acronym to guide you through evaluating such a site.
Watch this presentation called ACT UP: Evaluating Resources for Social Justice
All of these web sites are from academic and scholarly sources.