@article{v002a003,
 author = {Anupam Gupta and Aravind Srinivasan},
 title = {An Improved Approximation Ratio for the Covering Steiner Problem},
 journal = {Theory of Computing},
 year = {2006},
 pages = {53-64},
 publisher = {Theory of Computing},
 doi = {10.4086/toc.2006.v002a003},
 volume = {2},
 number = {1},
 URL = {http://www.theoryofcomputing.org/articles/v002a003},
 eprint = {toc:v002/a003},
}