Although the Armanen runes go back to List, Rudolf John Gorsleben distinguished himself from other völkisch writers by making the esoteric importance of the runes central to his world view. Goodrick-Clarke therefore refers to the doctrine of Kummer and Gorsleben and his followers as rune occultism, a description which also fits the eclectic work of Karl Spiesberger. Highly practical[further explanation needed] systems of rune occultism, influenced mainly by List, were developed by Friedrich Bernhard Marby and Siegfried Adolf Kummer (Goodrick-Clarke 1985: 160–62).