Columbia subject headings:
Harvard subject headings:
Aquatic pests--Azov, Sea of (Ukraine and Russia)
Aquatic pests--Black Sea.
Mnemiopsis leidyi--Azov, Sea of (Ukraine and Russia)
Mnemiopsis leidyi--Black Sea.
Princeton subject headings:
Aqatic pests--Azov, Sea of (Ukraine and Russia)
Aquatic pests--Black Sea.
Ctenophora--Azov, Sea of (Ukraine and Russia).
Ctenophora--Black Sea.