Again research about a short time in river (2-7)

I believe the answer is:

re-examine

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'a short time in river' is the definition.
I can't judge whether this definition defines the answer.

'again research' is the wordplay.
'again' becomes 're' (prefix meaning 'again').
'research' becomes 'examine' (I've seen this before).
're'+'examine'='RE-EXAMINE'

'about' acts as a link.

Can you help me to learn more?

(Other definitions for re-examine that I've seen before include "Study further" , "Look at again" , "Investigate again" .)

I've seen this clue in The Independent.

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