RE Broker Brooklyn
There are several things you can do as follows:
1) Drive around the neighborhood and look for for sale signs. It doesn't matter if they are "for sale by owner" or not. If no agent has told you about them they are probably not on MLS.
2) You can seek out "for sale by owners" either online or in the newspapers.
3) You can call as many real estate agents as you possibly can and ask each one of them if they have any office exclusives that are not on MLS (this could be time consuming).
4) Hire a great real estate agent to do all that for you.
If I can be of further assistance, please contact me direct. Good luck!
Cell: (917) 805-0783