I’ve never been terribly impressed or discouraged by Wikipedia’s quality of writing. It’s a basic (read grade school and middle school) encyclopaedia. If you are looking for something more substantive, you might be able to follow the links on the web. Or you might have to look elsewhere. I don’t recommend Wikipedia to my students. My sons use it often for their own perusal, but not for school.
The Guardian has an articleon Wikipedia’s accuracy from experts.
Sorry, I don’t remember how I got to that article. One of my regular blogs sent me there, though.