[MarkL444]

-1582--37
----3--8-
-389---5-
179-5-846
854---293
623489175
-----871-
-8--7-36-
-4--9-528

Ive been working on this for a while now and I can't find the next move. I had a friend check all the numbers to the answer in the back so I know its right. Ive done a lot of easy and medium puzzles but this was my first attempt at a hard. Maybe there is some technique I don't know about or whatever but I can't find the next move. Any help would be awesome.

thanks
mark