Let's call the columns numerically from left to right 1...9, and the rows alphabetically from top to bottom A...I. We'll refer to a cell using its row letter, followed by the column number.
We are going to use
the XY Wing technique
Let's consider the cells
B1, C2, D1
They conform to that pattern, with
- B1 being the middle cell, and
- C2, and D1 being the wings
We are sure that
either C2 or D1 must be a 9
which means
D2 can't be a 9
Now considering the cells
D2 and F3, they must contain 1 and 2.
They are a Naked Pair
⇒ D1 must be a 9
And then you'll be able to remove some candidates from
the G row.
You can take it from here or use this website to get hints or solve the puzzle either partially or completely.