Yep, read them. The first link isn’t a study, it is the page listing studies by “Denis R., PhD”, (quoted as the author of the info. in the website) and he has none regarding medical masks. The second link is a study of infection rates in people wearing N-95 masks vs. reg. surgical masks (about the same infection rate between the 2 <8.2%...not a study of “masks vs. no masks”. And like I said the 3rd link “sorta” supports the premise of the article, quote: “needs further study”, and “A secondary per-protocol analysis found that adherent use of N95 or surgical masks significantly reduced the risk for ILI in household contacts (hazard ratio 0·26, 95% CI 0·09–0·77) compared to non-adherent mask use or allocation to the control arm.”
It is “3 strikes and I move on” for “never heard of them Internet sources” for me. YMMV
And by the way, the articles I pointed to are not studies, they are reviews of studies, and include links and references to the data and text from those studies. You can follow the links in the articles and see the exact details of each referenced study.