BibTex format
@article{Ladak:2010:10.1038/nphys1628,
author = {Ladak, S and Read, DE and Perkins, GK and Cohen, LF and Branford, WR},
doi = {10.1038/nphys1628},
journal = {Nature Physics},
title = {Direct observation of magnetic monopole defects in an artificial spin-ice material"},
url = {http://dx.doi.org/10.1038/nphys1628},
year = {2010}
}