Reference works from which man copied wrongly (9)
I believe the answer is:
compendia
'reference works' is the definition.
'man copied wrongly' is the wordplay.
'wrongly' is an anagram indicator.
'man'+'copied'='mancopied'
'mancopied' with letters rearranged gives 'COMPENDIA'.
'from which' acts as a link.
(Other definitions for compendia that I've seen before include "Dome panic (anag) - summaries or collections" , "Lots of puzzles" , "set of encyclopaedias" , "summaries of work" , "books" .)