A book of great lasting value (5)

I believe the answer is:

atlas

'a book' is the definition.
(I know that atlas is a type of book)

'of great lasting value' is the wordplay.
'of' says the answer is hidden in the clue.
'ATLAS' is hidden within 'great lasting value'.

(Other definitions for atlas that I've seen before include "Giant" , "Sky carrier - map book" , "Plans" , "Collection of maps" , "Reference work" .)

I've seen this clue in The Irish Independent.

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