This is the 16666th most frequent Polish word.
wspomniana
"Mentioned" or "aforementioned."
'Wspomniana' is used as an adjective describing the book that has been previously mentioned in the context.
Wspomniana książka jest w bibliotece.
The mentioned book is in the library.
'Wspomnianej' is the feminine singular instrumental form, modifying 'podróży' (trip) and indicating it's the trip mentioned earlier.
Rozmawialiśmy o wspomnianej podróży wczoraj.
We talked about the mentioned trip yesterday.
The word 'wspomnianych' is in plural form and describes the 'problems' that were previously brought up or referenced.