Hipp, Ann, Michael Fritsch, Maria Greve, Jutta Günther, Marcel Lange, Christian Liutik, Beate Pfeifer, Mariia Shkolnykova and Michael Wyrwich: Comprehensive Patent Data of the German Democratic Republic 1949-1990—technical report and dataset overview. Jena Economic Research Papers #2022-011 Friedrich Schiller University Jena. https://ideas.repec.org/p/jrp/jrpwrp/2022-011.html