History of Rabi Yehuda Hachassid and his father, Anim Zmiros, his will and seforim, their authenticity, can you marry a niece? Same name as father in law? Yibum nowadays, Through a sheet???

Seder Hadoros, Chareidim, Reuven Margolis, Gemoroh Yevamos, brachos and Sotah, hagahos maimenios, RAMBAM, Magid Mishna, Chaim Falazhi, Kneses Hagdolah, Nodah B'hudah, Maharsha, Talmud Yerushalmi, Divrei Chaim (Tzanzer), Shem Aryeh, Chid"a, Rav Ovadia Yosef, R' Shneur Parnes

Source Sheet 1

Source Sheet 2