This author has not been identified. Look up 'Bengt Jonsson' in GoogleThis author has not been identified. Look up 'Tiziana Margaria' in GoogleThis author has not been identified. Look up 'Gustaf Naeser' in GoogleThis author has not been identified. Look up 'Jan Nyström' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Bernhard Steffen' in Google