 Along with the "Scott", "Stanley Gibbons", and "Yvert et Tellier" catalogs, the "Zumstein" (first published in Switzerland, 1909), and the "Michel" (first published in Germany, 1910) catalogs began publication.In 1934, the idea to celebrate an annual Postage Stamp Day was suggested by Hans von Rudolphi, a German philatelist.The idea was adopted rapidly in Germany, and gained later adoption in other countries.