@article{Voigt1997,
title = {Marshall-Peierls sign rule for excited states of the frustrated J1-J2
Heisenberg antiferromagnet},
author = {Andreas Voigt and Johannes Richter and Nedko B. Ivanov},
day = {01},
journal = {Physica A: Statistical and Theoretical Physics},
month = {Nov},
number = {3-4},
pages = {269--275},
url = {http://www.sciencedirect.com/science/article/B6TVG-3SPXB8W-10/1/4c9fbc14e290d0fb79efd4c576150413},
volume = {245},
year = {1997},
description = {Physica A},
keywords = {Heisenberg antiferromagnet }
}
::