The following publications are possibly variants of this publication:
- The complexity of minimizing certain cost metrics for k-source spanning treesHarold S. Connamacher, Andrzej Proskurowski. DAM, 131(1):113-127, 2003. [doi]
- Multi-Source Spanning Tree ProblemsArthur M. Farley, Paraskevi Fragopoulou, David W. Krumme, Andrzej Proskurowski, Dana Richards. sirocco 1999: 126-136
- Multi-Source Spanning Tree ProblemsArthur M. Farley, Paraskevi Fragopoulou, David W. Krumme, Andrzej Proskurowski, Dana Richards. join, 1(1):61-71, 2000.