@Daniel UchimotoConsider asking for recommendations from friends and business associates.

Why not try hiring a private detective to follow the kids home and then turn them into the Police (file a lawsuit against the parents, and a restraining order against the 14 year olds).You only need to find the home of one, and he will Rat Out the rest under the (perceived) "third Degree" questioning by the Police Officers.They might still throw rocks, but at least you can get a handle on it some what.Maybe a witch lives there, or a monster, or a ghost--who knows--it's kids..(???)

I have heard of Colleges and Universities having degrees in real estate, maybe that is something you can look in to as well. 

Operating expenses include all the expenses that are associated with operating your rental business, but DO NOT include the mortgage payment (principal and interest and PMI).

BJ Craig Craig Associates Casey Crawford Chinnery Evans and Nail

sounds like you need an attorney to deal with the landlord and condominium association.  

There is work involved in it, and the bigger you're holdings the more time you may have to spend Doctern' them.And if you take all of your time and spend it on business, your marriage may suffer and that means being liquidated in Divorce court with an MD Degree...

I check the docket online even before I have my local apartment association do a search.

Third:  contact your local rental owners association and sign up for any and all classes they offer. 

I don't know your tenants' price point or what he has been offering on, but the market here has cooled to a degree and the crazy bidding wars of the spring and summer have come and gone.