Bibliography in Catalogue of the British Museum.
Dr. Martin Luther's Werke. Kritische Gesamtausgabe, von Knaake und Andern. Weimar. 1883 ff. (The standard edition of the Reformer's writings, in course of publication, approaching completion. As yet have appeared more than fifty volumes of the Works, and, separately numbered: Die Deutsche Bibel, 4 vols., and Tischreden, 4 vols.).
Dr. Martin Luther's Briefwechsel, bearbeitet von E. L. Enders (vols. 12 ff. fortgesetzt von G. Kawerau). 1884 ff. (In course of publication; as yet 17 volumes).
Luther's Briefe, herausgegeben von W. L. M. de Wette. 6 vols. 1825-56.
Luther's Primary Works, translated by H. Wace and C. A. Buchheim. 1896.
The Works of Martin Luther, translated and edited by W. A. Lambert, T. J. Schindel, A. T. W. Steinhaeuser, A. L. Steimle and C. M. Jacobs. 1915 ff. (To be complete in ten volumes; as yet 2).
Luther's Correspondence and other Contemporary Letters, translated and edited by Preserved Smith. Vol. 1, 1913. Vol. II, in collaboration with C. M. Jacobs, 1918.
Conversations with Luther, Selections from the Table Talk, translated and edited by Preserved Smith and H. P. Gallinger. 1915.
Melanchthonis Opera, ed. Bretschneider und Bindseil. 1834 ff. In Corpus Reformatorum vols. i-xxviii.
J. Koestlin: Martin Luther, fuenfte Auflage besorgt von G. Kawerau. 2 vols. 1903. (The standard biography. The English translation made from the edition of 1883 in no wise represents the scholarship of the last edition).
A. Hausrath: Luther's Leben, neue Auflage von H. von Schubert. 1914. (Excellent).
H. Grisar: Luther. English translation by F. M. Lamond. 1913 ff. (Six volumes, representing the German three. A learned, somewhat amorphous work, from the Catholic standpoint, but not unfair).
H. Denifle: Luther und Lutherthum in der ersten Entwicklung. 3 vols. 1904 ff. (G. P. Gooch calls "Denifle's eight hundred pages hurled at the memory of the Reformer among the most repulsive books in historical literature"; nevertheless the author is so wonderfully learned that much may be acquired from him).
A. C. McGiffert: Martin Luther, the Man and his Work. 1911.
Preserved Smith: The Life and Letters of Martin Luther. 1914.
O. Scheel: Martin Luther, vom Katholizismus zur Reformation. 2 vols. 1917. (Detailed study of Luther until 1517. Warmly Protestant).
W. W. Rockwell: Die Doppelehe des Landgrafen Philipp von Hessen. 1904. (Work of a high order).
SECTIONS 2-5. The Revolution
Deutsche Reichstagsakten unter Karl V, herausgegeben von A. Kluckhohn and A. Wrede. 1893 ff. (Four volumes to 1524 have appeared).
Nuntiaturberichte aus Deutschland nebst ergaenzenden Aktenstuecken, herausgegeben durch das Koenigliche Preussische Institut in Rom. Erste Abtheilung 1533-59. 1892 ff. (As yet have appeared vols. 1-6, 8-12).
Emil Sehling: Die Evangelischen Kirchenordungen des XVI Jahrhunderts. 5 vols. 1902-13.
E. Armstrong: The Emperor Charles V. 2 vols. 1910.
Christopher Hare: A Great Emperor. 1917. (Popular).
O. Clemen: Flugschriften aus der Reformationszeit. 4 vols. 1904-10.
O. Schade: Satiren und Pasquille aus der Reformationszeit. 3 vols. 1863.
H. Barge: Der deutsche Bauernkrieg in zeitgenossischen, Quellenzeugnissen. 2 vols. (No date, published about 1914. A small and cheap selection from the sources turned into modern German).
J. S. Schapiro: Social Reform and the Reformation. 1909. (Gives some of the texts and a good treatment of the popular movement).
E. Belfort Bax: The Peasants' War in Germany. 1889. (Based chiefly on Janssen, and unscholarly, but worth mentioning considering the paucity of English works). See also articles Carlstadt, Karlstadt, T. Muenzer, Sickingen, etc. in the Encyclopaedia of Religious Knowledge and other works of reference.
W. Stolze: Der deutsche Bauermkrieg. 1908.
P. Wappler: Die Taeuferbewegung in Thueringen 1526-84. 1913.
B. Bax: Rise and Fall of the Anabaptists. 1903.
P. Wappler: Die Stellung Kursuchsens und Landgraf Philipps von Hefssen zur Taeuferbewegung. 1910.
F. W. Schirrmacher: Briefe und Akten zur Geschicte des Religionsgespraeches zu Marburg 1529 und des reichstages zu Ausburg, 1530. 1876.
H. von Schubert: Bekenntnisbildung und Religionspolitik 1529-30. 1910.
W. Gussmann: Quellen und Forschungen zur Geschichte des Augsburgischen Glaubensbekenntnises. Die Ratschlaege der evangelischen Reichsstaende zum Reichstag zu Augsburg. 3 vols. 1911.
Politische Korrespondenz des Herzog und Kurfuerst Moritz von Sachsen, hg. v. E. Brandenburg. 2 vols. (as yet), 1900, 1904.
S. Cardauns: Zur Geschichte der Kirchlichen Unions--und Reformbestrebungen 1538-42. 1910.
P. Heidrich: Karl V und die deutschen Protestanten am Vorabend des Schmalkaldischen Krieges. 2 vols. 1911-12.
G. Mentz: Johann Friedrich, vol. 3, 1908.
See also the works cited above by Armstrong, Pflugk-Harttung, Janssen, Pastor, The Cambridge Modern History, and documents in Kidd.
The Age of the Reformation · The Wunder Library — complete classics, free to read, with narration.