In dictionaries:
Yosef Yitzchak Schneersohn
Yosef Yitzchak (Joseph Isaac)His Certificate of Naturalization gives his name as Joseph Isaack.
Menachem Mendel Schneersohn
(September 20, 1789 – March 17, 1866) also known as the Tzemach Tzedek (Hebrew: "Righteous Sprout" or "Righteous Scion") an Orthodox rabbi, leading 19th-century posek, and the third rebbe (spiritual leader) of the Chabad Lubavitch Hasidic movement.
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