Österreichische Nationalbibliothek, Vienna
The Austrian National Library has a 'Nachlaß Otto & Marie Neurath', acquired by the library after Marie Neurath's death. It consists of around 8000 letters and other miscellaneous material. The letters are individually catalogued and are searchable online.
The miscellaneous material includes some legal and financial papers of the Isotype Institute; varied typescripts and correspondence relating to publications about Neurath and Isotype in the 1970s and 1980s; offprints of articles by Otto Neurath and others, and examples of Isotype in use.
Verein für die Geschichte der Arbeiterbewegung, Vienna
The former office of the Austrian Social Democratic Party and the associated printing house, Vorwärts, now houses the association for the history of the worker's movement. It has the Social Democratic Party archive which contains some material concerning the Gesellschafts- und Wirtschaftsmuseum in Vienna. The archive also has complete runs of the Party publications, Die Arbeiter-Zeitung and Der Kampf, for which Otto Neurath wrote many articles.
Vienna Circle Institute, University of Vienna
The Institute possesses a series of eleven charts, which were originally made by the Mundanaeum in the Hague for display in New York. They were bequeathed by Otto Neurath's son, Paul, to the Vienna Circle Institute, along with other papers (some of which are now in the University's Sociology Institute).
The Institute's library also contains the part of the Neuraths' working library relating to science and philosophy, which was given by the Vienna Circle Foundation, Amsterdam (now in Haarlem).