The sons of Midian were Ephah, Epher, Hanoch, Abida, and Eldaah. All these were the children of Keturah.
1 Chronicles 1:33
Surrounding context
1:32 Now the sons born to Keturah, Abraham's concubine, were Zimran, Jokshan, Medan, Midian, Ishbak, and Shuah. The sons of Jokshan were Sheba and Dedan.
1:33 The sons of Midian were Ephah, Epher, Hanoch, Abida, and Eldaah. All these were the children of Keturah.
1:34 And Abraham begot Isaac. The sons of Isaac were Esau and Israel.