Genesis 25:1-4
Then again Abraham took a wife, and her name was Keturah.
Nave's Topical Index—AKJV

1 Chronicles 1:32,33
Now the sons of Keturah, Abraham's concubine: she bore Zimran, and Jokshan, and Medan, and Midian, and Ishbak, and Shuah. And the sons of Jokshan; Sheba, and Dedan.
Nave's Topical Index—AKJV