Can anyone make recommendations about a smell coming from the hardwood floors?

I pulled up carpeting and then laminate in a bedroom. Underneath is old hardwood. The laminate pulled up very easy leaving no marks or damage to the floor underneath except for a 3 foot strip by the wall. This section was heavily glued down. We found that whatever type of glue this was was water soluble. When we put water on it, it smelled VERY bad but with enough mopping and scrubbing, we were able to remove the glue from the floor.

At this point, the floor looks like it doesn't have any glue on it, but the entire room still smells. It did not smell before we scrubbed the glue on the floors. (It has been over a month since we removed the glue - the "just let it air out" technique didn't work.)

Our two thoughts were to sand and refinish the floors, or to apply a moisture barrier and install a floating floor over top. We worry if we sand the floors, then the odor will still be there. The thought on the moisture barrier is that it would provide a "smell barrier" as well, but I don't know if it would.

Does anyone know what type of glue we uncovered or does anyone have any experience in this area? Any advice would be helpful.

The house was built in the 1940s.