German research institutions offer a variety of short-term grants for PhD students. For example, if you are researching Prussian history, you can apply for a grant from the Geheimes Staatsarchiv Preussischer Kulturbesitz in Berlin. If you are interested in the religious history of early modern Europe, the Institute for European History in Mainz offers funding. The application period for both programs is ending soon. The Research Library of Gotha offers funding to researchers.