Persistent identifier https://phaidra.univie.ac.at/o:1684824
Handle https://hdl.handle.net/11353/10.1684824
URI https://valep.vc.univie.ac.at/virtualarchive/public/Philipp_Frank_Institute_for_the_Unity_of_Science_to_Morris_1950-07-07_L_Original/dv:952558