Consider the well known transportation problem: There are $m$ supply nodes, $n$ demand nodes and $k$ feasible arcs. Every node has a integer supply or demand, and the arcs have integer costs, used linearly, i.e. if $x$ units are shipped along an edge annotated with $c$, the cost is $c\cdot x$.
I have an article by Kleinschmidt and Schannath describing an $O(m\log m (k+n\log n))$ solution.
Is this the currently best algorithm, or has there been an improvement since 1995?
(My search turned up an article by Brenner from 2008, but I don't have access to it. The title talks about the "unbalanced Hitchcock transportation problem", I am not sure it is the problem considered here).
Would this be the right algorithm to implement?
Which libraries provide implementations of the transportation problem?