Deutsche National Bibliothek includes bibliographic information about Stoeltzner’s 3 articles but no reproduction or PDF. https://portal.dnb.de/opac.htm
Munchener DigitalisierungsZentrum Digitale Bibliothek does not have any information on Stoeltzner's articles. https://www.digitale-sammlungen.de/en
Wellcome Trust has a book authored by Wilhelm Stoeltzner:
Ueber die Anwendbarkeit der verticalen Extension bei der Behandlung von Oberschenkelfracturen rachitischer kinder. Stoeltzner, Wilhelm, 1872- Date: [1895] . In English: On the applicability of vertical extension in the treatment of Femoral fractures in rachitic children.