This author has not been identified. Look up 'Ulrike Golas' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Enrico Biermann' in GoogleThis author has not been identified. Look up 'Hartmut Ehrig' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Claudia Ermel' in Google