5 1 .. . . . . 7 .	.. 9 .. 1 6 8 . . .	.. 4 .. . . . 3 1 9
.. 8 7 . . 3 . . .	9 .. .. 6 7 4 .. .. ..	. . . . . . 4 7 2
. . . 7 4 9 . . .	3 2 7 . . .. . . .	. . . . . . 7 8 6
In the second block, 1 can not be in the first row because of the 1 in the first block. It can not be in the third row because of the 1 in the third row in the third block. Thus it has to be in the middle row. There is just one slot left in that row.
In the middle block, 7 can not be in the upper row because of the 7 in the left block. It can not be in the lower row because of the 7 in the lower row in the right block. Thus it has to be in the middle row. There is just one slot left in that row.
In the second block, 7 can not be in the middle row because of the 7 in the left block. It can not be in the third row because of the 7 in the third row in the right block. Thus it has to be in the upper row. There is just one slot left in that row.