https://www.deutsche-digitale-bibliothek.de/person/gnd/133111040
Otto Winkelmann - Deutsche Digitale Bibliothek
otto winkelmanndeutschedigitalebibliothek
https://archive.org/details/philippvonschwa02winkgoog
Philipp von Schwaben und Otto IV. von Braunschweig : Winkelmann, Eduard [August], 1838-1896. [from...
Book digitized by Google from the library of Harvard University and uploaded to the Internet Archive by user tpb.
philipp von schwaben
https://archive.org/details/philippvonschwa00winkgoog
Philipp von Schwaben und Otto IV. von Braunschweig : Winkelmann, Eduard August, 1838-1896 : Free...
Book digitized by Google from the library of Oxford University and uploaded to the Internet Archive by user tpb.
philipp von schwaben