Credits as a source (5)
I believe the answer is:
cites
'credits as a source' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cites that I've seen before include "Quotes; mentions in official despatch" , "Mentions as an example" , "Quotes (an author)" , "Quotes as authority" , "Quotes; names" .)