Höffler, Felix Max Planck Institute for Research on Collective Goods, Max Planck Society;
http://www.sciencedirect.com/science/article/pii/S016771871100004X (Any fulltext)
Höffler, F., & Kranz, S. (2011). Legal Unbundling Can Be a Golden Mean Between Vertical Integration and Ownership Separation. International Journal of Industrial Organization, 29, 576-588.