Muwatta Malik #173

Yahya related to me from Malik from Nafi that Abdullah ibn Umar used to recite in all four rakas as when he prayed alone - in every raka the umm al-Qur'an and another sura from the Qur'an. Sometimes he would recite two or three suras in one raka in the obligatory prayer. Similarly, he recited the umm al-Qur'an and two suras in the first two rakas of maghrib.