elementary #218
elementary #533
intermediate #344
advanced #31
this last one in particular I found in another problem collection and the problem is simply missing stones on the outside. The problem should be

    [go]$$B
    $$ +------------------
    $$ | . O . X O . . . .
    $$ | X X X X X O . O .
    $$ | O O O O X O . . .
    $$ | . . . , X O . . .
    $$ | . O O X X O . . .
    $$ | . X X . . O . . .
    $$ | . O O O O . . . .
    $$ | . . . . . . . . .
    $$ | . X . X . . . . .
    $$ | . . . , . . . . .[/go]
    
advanced #36