Economics rather strongly deprecates both history and philosophy, often offering only a brief overview of the former and a highly digested form of the latter.

One windfall of the World Wide Web are the fundamental texts now online. Many legally, through the Internet Archive, or various libraries -- the Online Library of Liberty and Mises.org, as much as I disagree with their ideological bases, have quite good collections. More in the form of illicit copies. LibGen, BookXX.org, and Sci-Hub offer access to many books and articles. Wikipedia is strong in economics, in particular offering biographies of many particular authors and theorists.

Worldcat (https://www.worldcat.org/) will help you track down published books at libraries worldwide.

Having studied economics at Uni, I'm making up for many deficiencies of my curriculum.