Hi i'm new to this forum and to sudoku. Im stuck on a puzzle and not sure on the best way to proceed. Any help on the techniques needed to finish solving this would be appreciated.

So far:

869|542|137

534|718|629

271|396|485

---------------

***|625|***

***|431|***

***|987|***

---------------

186|274|953

743|859|216

952|163|874

Candidates for middle 3 rows;

(43)(19)(78)***(73)(49)(18)

(6)(29)(578)***(57)(69)(28)

(346)(12)(5)***(35)(46)(12)

Hopefully that is quite clear. Im completely stuck, any ideas on what to do next will be appreciated

Thanks