Professional referral sources for acquisition targets

Any insights or experience with different types of professionals for referring opportunities? Trying a few but don't yet have any results to report so I'd be curious to hear whether this has been successful for anyone here. The idea is to find a professional that would be early enough in the process that a transaction hasn't started, but where someone might be saying they're looking to retire.

Lawyers? Corporate Accountants? Tax planning?

I tried a few friends in wealth management who all echo'd that they don't really see entrepreneurs until they've had liquidity for the most part.