This link will take you to an article from the Christian Research Institute on the subject. You may view it as an online article or go to the bottom of the page and click on the pdf format and save it.

The title is Who Were the Sons of God in Genesis 6?

The following link will bring it up in your browser. (You may need to copy this and paste it into the address bar on your browser

http://equip.org/articles/who-were-the-sons-of-god-in-genesis-6-

or back to the beginning

http://doncassel.com/