I've learnt that historains have published books completed with the assistance of researchers. In a TV programme you will notice that everyone receives a credit - the same thing needs to occur with books. A good deal is being published on the First World War (again), now for the 100th, previous 'biggies' being 50, 60, 75 and 90. I am learning that X and Y were written using researchers - credit them! Increasingly in our connected and open world collaborative works should be undertaken, I'm sure they'd be better for it.