Literary pieces written for trials (6)
I believe the answer is:
essays
I believe this clue is a double definition.
'literary pieces' is the first definition.
(I've seen this in another clue)
'trials' is the second definition.
(I've seen this in another clue)
'written for' is the link.
(Other definitions for essays that I've seen before include "Tries to write compositions?" , "literary work" , "Compostions and tracts" , "Tries for theses?" , "Compositions, articles" .)