The first attempt at publishing catalogs for Marklin Z collectors were the Koll’s Katalog’s of 1996 and 1997, they formed the basis for an archive including a chronological list with very good illustrations. As with all Koll’s catalogs prices were provided in DM, but with all collectibles prices cannot be frozen in time and as of this writing certain valuations are either too low or too high if one were to track selling prices on the secondary market today. Eliminate the pricing feature and we are left with a very good archive of Marklin Z produced until 1996 and 1997 respectively. These catalogs are highly sought after, they were produced in small number, and they are long out of print. Every serious collection needs books for reference thus it can be important to study the hobby with these Koll’s catalogs.