BibTex format
@article{Levi:2013:10.1103/PhysRevLett.110.150402,
author = {Levi, F and Mintert, F},
doi = {10.1103/PhysRevLett.110.150402},
journal = {PHYSICAL REVIEW LETTERS},
title = {Hierarchies of Multipartite Entanglement},
url = {http://dx.doi.org/10.1103/PhysRevLett.110.150402},
volume = {110},
year = {2013}
}