Cross reference
Judges 12:9
9 He had thirty sons; and thirty daughters he sent abroad, and thirty daughters he brought in from abroad for his sons. He judged Israel seven years.
Judges 10:4
4 He had thirty sons who rode on thirty donkey colts, and they had thirty cities, which are called Havvoth Jair to this day, which are in the land of Gilead.
Judges 12:14
14 He had forty sons and thirty sons' sons, who rode on seventy donkey colts: and he judged Israel eight years.