868 F.2d 1313 (2d Cir.), cert. denied, 493 US 883 (1989)
We established the point that defendant’s joint authorship with plaintiff of an underlying medical work did not entitle him to claim copyright co-ownership or fair use of the material newly added by plaintiff to derivative work based on the co-authored underlying work where the defendant had not participated in preparing the new material to update the original work.