This author has not been identified. It may be one of the following persons: Look up 'Sven Apel' in GoogleThis author has not been identified. Look up ' Hendrik Speidel' in GoogleThis author has not been identified. Look up ' Philipp Wendler' in GoogleThis author has not been identified. Look up ' Alexander von Rhein' in GoogleThis author has not been identified. Look up ' and Dirk Beyer' in GoogleThis author has not been identified. It may be one of the following persons: Look up 'Sven Apel' in GoogleThis author has not been identified. Look up ' Hendrik Speidel' in GoogleThis author has not been identified. Look up ' Philipp Wendler' in GoogleThis author has not been identified. Look up ' Alexander von Rhein' in GoogleThis author has not been identified. Look up ' and Dirk Beyer' in Google