Wikipedia
Between 1858 and 1902, the Händel-Gesellschaft, or "German Handel Society," produced a collected 105-volume edition of the works of George Frideric Handel. Even though the collection was initiated by the society, many of the volumes were published by Friedrich Chrysander working alone (Chrysander was the major contributor for almost all of the volumes). The wording on the title page of the volumes is "Georg Friedrich Händel's Werke. Ausgabe der Deutschen Händelgesellschaft" which translates as "Georg Friedrich Handel's works. Edition of the German Handel Society". Chrysander's work has been criticised, however the scale of his achievement is also praised. The collection's abbreviation of "HG" can be used to identify individual works by Handel; for example Handel's Messiah can be referred to as "HG xlv" (with the Roman numerals "xlv" indicating that the work is in volume 45). For practical use, the HG system has been superseded by the HWV numbering system. The 105 volumes do not contain the complete works of Handel—with at least 250 of his works unpublished in the collection.