Cross reference
Judges 12:9
9 He had thirty sons, and thirty daughters whom he sent to other places, and he got thirty wives from other places for his sons. And he was judge of Israel for seven years.
Judges 10:4
4 And he had thirty sons, who went on thirty young asses; and they had thirty towns in the land of Gilead, which are named Havvoth-Jair to this day.
Judges 12:14
14 He had forty sons and thirty sons' sons who went on seventy young asses; and he was judge of Israel for eight years.