This is the 16625th most frequent Polish word.
wrocławskim
"Wrocławskim" means "of/from Wrocław" (relating to the city of Wrocław).
Here, 'wrocławskim' is an adjective describing the block of flats which is located in Wrocław.
Mieszkam w wrocławskim bloku.
I live in a block of flats in Wrocław.
In this sentence, 'wrocławskim' is an adjective modifying 'festival', indicating the location or origin of the festival.
Uczestniczyłem w wrocławskim festiwalu muzycznym.
I participated in the music festival in Wrocław.
Here, 'wrocławskim' describes the scientific journal, specifying its association with Wrocław.