@article{article24197bee,
title   = {Algorithms to solve qualitative problems in power system state estimation},
author = {London Junior, João Bosco Augusto and Bretas, Arturo Suman and Bretas, Newton Geraldo},
year = {2004},
doi = {10.1016/j.ijepes.2004.04.004},
journal   = {International Journal of Electrical Power and Energy Systems}
}