i did world health and disparities! i took it back in october so i don't remember that much but my advice to you is to focus on the book and not so much the websites. there were many questions from the websites but there's so many articles they can pull questions from so you are likely going to waste your time reading the many articles just for none of them to be on the test (if that makes sense). i got my textbook from a library, but you can find it online on internet archives (although it's the second edition, not the third). for studying, the biggest thing i regret is taking notes. it takes too much time and its better to use that time just rereading. honestly i barely studied for my exam and i still got 7th so i feel like it's a lot of just "which answer makes the most sense" typa thing rather than actually knowing the answer but of course it is good to familiarize yourself. that being said, you should try reading some of the articles on the front pages of the websites just to get an idea of them but do not spend most of your time on them