Angry allusion identifying comparison in book (5-9)

I believe the answer is:

cross-reference

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'comparison in book' is the definition.
'cross-reference' can be an answer for 'comparison'. I am not certain of the 'in book' bit.

'angry allusion' is the wordplay.
'angry' becomes 'cross' (cross can mean annoyed or angry).
'allusion' becomes 'reference' (I've seen this before).
'cross'+'reference'='CROSS-REFERENCE'

'identifying' is the link.

Can you help me to learn more?

I've seen this clue in The Times.

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