Plural and feminine definitive articles and even indefinite articles (the, a/an) are the exact same in Nominative, Akkusative, and Genitive case. It's worth noting that "Von" + noun typically replaces the Genitive case.
In the dative case, the definite and indefinite articles are different for feminine and plural.
Fem. Def. Article (Dat.): Der
Fem. Indef. Article (Dat.): Einer
Plur. Def. Article (Dat.): Die
Plur. Def. Article (Dat.): Keinen
To help remember!