Musannaf Ibn Abi Shayba 26:53

Ibn Fudayl narrated to us, from Bassam, from Fudayl, from Ibrahim, regarding a man who left behind his two daughters, the daughter of his son, and a son of his son who is lower than her: For his two daughters are two-thirds, and what remains for the son of his son is returned to those above him and those with him among the daughters, according to the opinion of Ali and Zayd, for the male is like the portion of two females, and it is not returned to those below him. And according to the opinion of Abdullah, for his two daughters are two-thirds, and for the son of his son is what remains; he does not return anything to his sister nor to those above him, because he (the deceased) has completed the two-thirds. Abu Bakr said: This is out of nine in the opinion of Ali and Zayd, so the two daughters receive the two-thirds, and three shares remain; for the son of the son are two shares, and for his sister is one share. And in the opinion of Abdullah, it is out of three shares; for the two daughters are the two-thirds, which is two shares, and for the son of the son is what remains, which is one share.