Tip for doing research: follow leads even when you're not sure they are going anywhere.
If you see the name of a person or organization mentioned in context of someone/something you're looking into, take a second to find out about them & look for other connections they may have with the person you're researching.
They don't spell out for you who is in business with who. You've got to notice when names show up together & look deeper if you want to find new leads.