Researching SDLC methods and finding so many articles with poor English and grammatical errors. Are there reputable resources out there discussing the different methods?

I don't know why, but nearly all of the resources I've come across when Google-searching the different methodologies, e.g. spiral, waterfall, prototyping, agile etc., all seem to have grammatical errors or outright poor English. Maybe it sounds superficial, but I get distracted when using resources with lots of mistakes, and trust the quality less.

Are there good resources for learning more about the software development life-cycle methodologies, which have fewer errors?