zbirka

1. collection
   Moj deda ima veliku zbirku starih maraka. — My grandfather has a large collection of old stamps.
   Muzej je dobio novu zbirku slika. — The museum received a new collection of paintings.
2. (of texts, exercises) collection; anthology; workbook
   Izašla mu je nova zbirka pesama. — His new collection of poems has come out.
   Za prijemni radim zadatke iz zbirke. — I'm doing problems from the workbook for the entrance exam.

"Zbirka zadataka" means a book of exercises or problems.