@article{GaspersKoivistoLiedloffOrdyniakSzeider15,
 author = {Serge Gaspers and
Mikko Koivisto and
Mathieu Liedloff and
Sebastian Ordyniak and
Stefan Szeider},
 doi = {10.1016/j.tcs.2015.05.012},
 journal = {Theoretical Computer Science},
 pages = {49--58},
 title = {On finding optimal polytrees},
 url = {http://dx.doi.org/10.1016/j.tcs.2015.05.012},
 volume = {592},
 year = {2015}
}