@article{DBLP:journals/corr/cs-GT-0409028,
author = {Andreas U. Schmidt},
title = {On Incentive Systems Based on Multi-Level Marketing of Virtual
Goods},
journal = {CoRR},
volume = {cs.GT/0409028},
year = {2004},
ee = {http://arxiv.org/abs/cs.GT/0409028},
bibsource = {DBLP, http://dblp.uni-trier.de}
}