| Collecting | Description |
| Collectify | Software to organize your collection |
| CatalogIt | Really good cloud based collection management software |
| Conradi | Description |
| Another Conradi site | This site is maintained Conradis family (Dr. Waldemar Horster and Gabriele Felizitas Horster) |
| Gutschow Haus | Information about the "Gutschow" house - Friedrichstrasse 17 in which Horsters store was located |
| Wikipedia | Wikipedia entry for Conradi Horster |
| Misc | Description |
| Magic Circle of Germany | Homepage of the "Magic Circle of Germany" |