Is it okay to reference something well agreed by only one source, [e.g. 1 source]? I am wondering if it is okay write something like: 

"Many scholars hold the view that this is like that" and then give one example reference (e.g. Gans et.al. 1965) ? 

The reason I am wondering because it is generally accepted and no one seems to disagree on that. Is it better (1) not to reference at all, (2) reference the most original paper and skip e.g., or (3) mention few?
If something is considered common knowledge in the field (for instance, Newton’s second law in a physics paper), then no reference is required. If it’s been developed multiple independent times, though, I’d use more than one reference to establish it.