Olaf Sannum and Axel Sannum

I know this is a long shot, but im gonna try anyway. Im looking for help in how i could find Olaf and Axel Sannum. I know they went to the US when they where in ther 20's (1910 - 1920). But sadly thats all the info i could find. I got this information when i was talking to my grandmother last week. If someone can help me in some way it will be of great help. Bernt Sannum