Everywhere. Everyone. Every event.
All news outlets, regardless of slant or supposed credibility, The Library, documentaries, interviews, conversations with people I know or meet, 58 years of past information/fake news/propaganda I read combined with what came out much later to be the real story, and of course the occasional posts here that provide evidence to back up their post.
I assume it is all lies, try to discern the motives and methods behind the lies, follow the money/power, then search for verification of the slivers of truth that cannot be debunked.
Then add common sense and logical reasoning.
When you are taught this process at age 5 and look back nearly 6 decades later, you see there has never been a free or honest press and our government has been an elaborate front controlled by the most vile criminals in the world for at least 100 years.