Institution: National Library of Estonia OR Institution: University of Tartu Library OR Institution: University Library of Regensburg OR Institution: University and Regional Library of Tyrol OR Institution: National Library of Technology (Czech Republic) OR Institution: Universitätsbibliothek der Humboldt-Universität zu Berlin OR Institution: The Swiss National Library OR Institution: University Library in Bratislava Author: Keller, Gottfried 1819-1890 Author: Christiansen, Hans