Imaskarcana

Detailed in Lost Empires. Crown of the rulers of Imaskar, contains knowledge of its political history. Currently believed to be in the ruins of Inupras.

Detailed in Underdark (page 77). It's a big book that answers questions, and imparts spells like Meteor Swarm and Time Stop.

Detailed in Lost Empires. Scepter of the rulers of Imaskar, contains all military knowledge. Currently in the ruins of Inupras.

Mentioned in Lost Empires Web Enhancement in an adventure. Contains all knowledge about extradimensional magic.