Board Thread:Off Topic/@comment-108.34.238.226-20150112025307/@comment-25606771-20150112031932

Once you sell them you cant get them back. The only exception is if you sold the dragon scroll to Urag before you had Dawnguard installed. But, even if you sell it back to him for the second time, you still won't be able to buy it back. You'll never be able to remove them from your inventory even after the quest, so selling is the only option to get rid of them.