Der Herzog von Reichstadt (Stojanović, Petar)

It is very unlikely that this work is public domain in the EU, or in any country where the copyright term is life-plus-70 years. However, it is in the public domain in Canada (where IMSLP is hosted) and other countries where the term is life-plus-50 years (such as China, Japan, Korea and many others worldwide). As this work was first published before 1925 or failed to meet notice or renewal requirements to secure statutory copyright with no "restoration" under the GATT amendments, it is very likely to be public domain in the USA as well.