Musannaf Ibn Abi Shayba 26:52

Ibn Fudayl narrated to us, from Bassam, from Fudayl, from Ibrahim, who said: Regarding his two sisters from his father and mother, they get two-thirds, and for his brothers from his father and his sisters, what remains is for the male the like of the portion of two females, according to the opinion of Ali and Zayd. And according to the opinion of Abdullah, for his two sisters from his father and mother is two-thirds, and what remains is for the males of his brothers, excluding their females. Abu Bakr said: This, in both opinions, is out of three shares. For the sisters and the daughters is two-thirds, and one-third remains, so it is between the brothers and the sisters, or between the daughters of a son and a daughter, for the male the like of the portion of two females.