  The problem considered is the following. Given a graph with edge weights
satisfying the triangle inequality, and a degree bound for each vertex, compute
a low-weight spanning tree such that the degree of each vertex is at most its
specified bound. The problem is NP-hard (it generalizes Traveling Salesman
(TSP)). This paper describes a network-flow heuristic for modifying a given
tree T to meet the constraints. Choosing T to be a minimum spanning tree (MST)
yields approximation algorithms with performance guarantee less than 2 for the
problem on geometric graphs with L_p-norms. The paper also describes a
Euclidean graph whose minimum TSP costs twice the MST, disproving a conjecture
made in ``Low-Degree Spanning Trees of Small Weight'' (1996).
