ὧν

From LSJ

ἐλάττω ἔχειν γῆν τὸν ἀγρὸν ἐπιστολῆς Λακωνικῆς → own a farm smaller than a Laconian letter, own a tiny farm

Source

French (Bailly abrégé)

gén. pl. du relat. ὅς, ἥ, ὅ.

Russian (Dvoretsky)

ὧν: gen. pl. к ὅς, ἥ, ὅ.