Research of this kind, based on written sources is very uncommon concerning the Nordic countries. The only work based on written sources that has dress in the Middle Ages as its main topic is Altwestnordische Kleiderkunde by Hjalmar Falk. It is a thorough investigation of different literary sources, mainly Icelandic and Norwegian sagas, but also documents like letters and wills, with the aim to study the mediaeval dress. Types of fabric and other materials used in dress are also treated, likewise which colours were used etc. The main goal of his work is to set a terminology for mediaeval dress in Norse sources, not to investigate the development of dress.