How to avoid refection from glass

I want to take a picture of a poster framed in glass frame, how to minimize all the glare and reflection from the glass?

try a circular polarizer. Should help some.

A polorized filter and shoot from an angle. If you want the shot from straight on and there is light behind you the best thing to do is remove the glass. Ive tried this befor, It just takes some trial and error.

Another suggestion is to stand back a large distance and zoom in on the picture using a off camera strobe. The flash should be out of angle considering the distance, but you should be still able to illuminate your object without the reflection. Use of the polarizer is good as well.