Shalidor's Insights (Quest)

Background
"Urag gro-Shub is looking for writings by the Arch-Mage Shalidor, so that he can translate them into something useful for the College. He's asked that I attempt to find another copy for him."

Walkthrough
Once you have been admitted to the College of Winterhold you have access to the Arcanaeum. The Arcanaeum is tended by an old Orc named Urag gro-Shub. You have to ask Urag if he needs any special books to be found. Urag will talk about the Arch-Mage Shalidor and his understanding of magic. Urag will then ask you if you wish to find Shalidor's Insights for him. Accept.

In the chest located on the map a copy of Shalidor's insights is found. Return the book to Urag and receive 30 gold. Urag says he'll need a couple of days to translate the book. Wait 48 hours and ask Urag how the research is coming along, and—if you've waited long enough—he'll say they've completed the translation, and gives you three Shalidor's Insights: These are scrolls which lower the cost and increase the duration of spells for 120 seconds. The kind of scroll you get depends on which tree (Destruction, Alteration, Conjuration, ...) you have the highest level on. Uncommonly, the Dragonborn will get a random magic skill increase (Destruction, Alteration, Conjuration, ...). This increase does NOT count as one of the five training points each level but it functions in the exact same manner as it would a trainer.

Known locations

 * As a Radiant quest, locations will vary.

Bugs

 * The book cannot be returned until after the Staff of Magnus has been obtained.
 * If Vokun has already been killed without looting the scroll, then it may not be possible to open the gates to get back into the treasure room behind Vokun. If a follower is present, jump on the pillars in the room where Anska is, then use whirlwind sprint to reach the ledge where the treasure room is. Use unrelenting force to push the follower through the gate (several tries will be needed, just wait an hour to try again); have the follower pull chain to open the gate so the treasure room can be accessed to get the book.
 * If the player already has the required book, a dialogue to give it over will not appear, and going to the location will not help.
 * the Book may be dropped using console commands (player.drop "refID"). The refID can be one of eight different ones, as listed below. After picking the book up again the quest jumps forward to the point were you can just turn it in. (000F6275; 000F6276; 000F6277; 000F6278; 000C1E77; 000C1E78; 000C1E79; 000C1E7A)
 * If told to fetch the book in an area that is already cleared, it will not be there (may possibly reappear once the dungeon refreshes).
 * After the quest is complete and the scrolls are obtained from Urag gro-Shub, the dialogue option with him to start the same quest still exists. Selecting this same option initiates the conversation in which Urag asks the Dragonborn if he/she has ever heard of Shalidor, and the quest reappears on the journal. However, no quest marker is shown.
 * This quest can be done multiple times. Scrolls from all magic schools (except enchanting) can be obtained this way.
 * Sometimes a skill level will be given as a reward, but this is extremely rare.