Second Battle of Ypres (English Wikipedia)

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worldcat.org

Häften 1932, p. 41. Häften, Hans von, ed. (1932). Der Weltkrieg 1914 bis 1918: Militärischen Operationen zu Lande Achter Band Die Operationen des Jahres 1915. Die Ereignisse im Westen im Frühjahr im Sommer und Osten vom Frühjahr bis zum Jahresschluß [Military Operations on land: The Operations of 1915. The events in the West in the Spring and Summer, in the East from the Summer to the Year's End]. Vol. VIII (online scan ed.). Berlin: Verlag Ernst Siegfried Mittler und Sohn. OCLC 838300036. Retrieved 25 November 2013 – via Oberösterreichische Landesbibliothek.
Macpherson 1923, pp. 271–274. Macpherson, W. G. (1923). Medical Services General History: The Medical Services on the Western Front, and during the Operations in France and Belgium in 1914 and 1915 (pdf). History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (online ed.). London: HMSO. OCLC 83853880. Retrieved 19 November 2019.
Edmonds 1928, pp. 150, 178. Edmonds, J. E. (1928). Military Operations France and Belgium, 1915: Battles of Aubers Ridge, Festubert, and Loos. History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (1st ed.). London: Macmillan. OCLC 58962526.
Macpherson 1923, pp. 274–277. Macpherson, W. G. (1923). Medical Services General History: The Medical Services on the Western Front, and during the Operations in France and Belgium in 1914 and 1915 (pdf). History of the Great War Based on Official Documents by Direction of the Historical Section of the Committee of Imperial Defence. Vol. II (online ed.). London: HMSO. OCLC 83853880. Retrieved 19 November 2019.