Grätz, Geschichte der Juden, vol. X, Index sub "Polen," particularly the chapter on Sabbatai Zevi.
----, Frank und die Frankisten, Breslau, 1868.
Dubnow, "Jacob Frank and his Christianizing Sect," Voskhod, 1883, Book I et seq.
----, "The History of Frankism according to newly discovered sources," Voskhod, 1896, Books III-IV.
Kraushar, Frank i Frankiźci ("Frank and the Polish Frankists"), Cracow, 1895. Two volumes [P].
Balaban, "Notes on the History of the Frankist Sect," He-`Atid, vol. V, Berlin, 1913.
Horodezki, Mystisch-religiöse Strömungen unter den Juden in Polen im XVI-XVIII Jahrhundert, Leipzig, 1914.
Dubnow, "The Social and Spiritual Life of the Jews in Poland in the First Half of the Eighteenth Century," Voskhod, 1899, Books I-II.
----, "Introduction to the History of Hasidism," He-`Atid, vol. III, Berlin, 1911.
----, "The Rise of Hasidism and Tzaddikism. History of the Hasidic Schism. The Religious Struggle, etc.," Voskhod, 1888-1893.