Moses Charikar, Tom Leighton, Shi Li, Ankur Moitra. Vertex Sparsifiers and Abstract Rounding Algorithms. In 51th Annual IEEE Symposium on Foundations of Computer Science, FOCS 2010, October 23-26, 2010, Las Vegas, Nevada, USA. pages 265-274, IEEE Computer Society, 2010. [doi]
Abstract is missing.