1 Kings 15:7
Now the rest of the acts of Abijam, and all that he did, are they not written in the book of the chronicles of the kings of Judah? And there was war between Abijam and Jeroboam.
Nave's Topical Index—AKJV

2 Chronicles 13:1
Now in the eighteenth year of king Jeroboam began Abijah to reign over Judah.
Nave's Topical Index—AKJV