: There are web portals and directories that index special issues of magazines, especially if they are popular or have a dedicated following.
They archive all German publications. While you cannot download copyrighted material for free, their catalog can confirm the exact publication year and availability of Issue 23. sonnenfreunde sonderheft magazine 23 link
: Archival websites like LastDodo feature historical catalogs detailing issue numbers, years of publication, and variant covers for collectors seeking to catalog their physical estate collections. : There are web portals and directories that
