Biologisch-dynamische Präparate rühren

Rudolf Steiners propositions for stirring Bio-Dynamic Cow Horn Manure Preparation and Horn Silica Preparation and actual practices of hand stirring: Comparison with the help of practical observations and the terminology of vortex theory. (H. J. Lugt 1979 / 1983) Practical consequences, questions for further research. With demonstrations (and practical exercises).