@article{v008a015, author = {Goel, Ashish and Post, Ian}, title = {One Tree Suffices: A Simultaneous $O(1)$-Approximation for Single-Sink Buy-at-Bulk}, year = {2012}, pages = {351--368}, doi = {10.4086/toc.2012.v008a015}, publisher = {Theory of Computing}, journal = {Theory of Computing}, volume = {8}, number = {15}, URL = {https://theoryofcomputing.org/articles/v008a015}, }