A "Sifra" midrash without attribution is assumed to be from R' Yehudah: Shabbat 137a; Eruvin 96b; Keritot 22a
The Talmud learning a "Derash" analysis, and then asking, "But what is the basic translation? [Pashteih diKra beMai Ketiv?]": Eruvin 23b
Two "Sifra" midrashim directly contradicting each other: Keritot 7a
