I'm wanting to find online business directories in USA, either a variety of local small biz vendors, or regional vendors in a related niche.

Are there any easy ways to find them?

Not huge ones, like Angi, but the kinds of sites that IMers like to set up.

[Edited by moderator: no solicitation in posts, please]

EDIT: I'm simply looking for ways to search for them. For instance, you can find Wordpress sites by searching for "powered by wordpress". Perhaps there are a dozen common scripts used for directories; surely they all have some telltale signatures that make them easy to find. I don't want to buy anything.