This organization publishes a critical edition of Bruckner's and Hugo Wolf's works. It is represented by Barenreiter of Kassel.
from Barenreiter's site: Founded in 1933 by the Internationale Bruckner Gesellschaft (International Bruckner Society: IGB) for the purpose of publishing a Complete Critical Edition of the works of Anton Bruckner. The General Editor of the old Bruckner Complete Edition was Robert Haas, together with Alfred Orel; after Orel’s resignation, Leopold Nowak became co-editor from 1937. In 1938 the IBG was absorbed into the German Bruckner Society, and Musikwissenschaftlicher Verlag Wien (MWV) was dissolved in Vienna and transferred to Leipzig. In 1944 it was renamed Bruckner-Verlag Leipzig. Shortly before the end of World War II the publishing stock was destroyed by bombing.
In 1946 the IBG was re-established and the headquarters of MWV moved to Vienna, with the aim of a new start for the Bruckner Complete Edition. Between 1951 and 1989 a major part of the editions of the Complete Works of Anton Bruckner were published under the general editorship of Leopold Nowak; from 1989-2002 Herbert Vogg continued the editorship of the Complete Works in the spirit of Nowak. From 1960 MWV also published the Critical Complete Edition of the works of Hugo Wolf under the general editorship of Hans Jancik, followed by Leopold Spitzer from 1991. As well as the two Complete Editions, the publishing programme also includes musicological literature, specialising in Anton Bruckner and Hugo Wolf, including a Complete Edition of the letters of Hugo Wolf and the publication series of the Anton Bruckner Institut Linz and the Anton Bruckner Research Centre at the Austrian Academy of Sciences.
In 2011, work began on a new edition of the complete works of Anton Bruckner under the title “New Anton Bruckner Complete Edition”.