Güth, Werner Max Planck Institute for Research on Collective Goods, Max Planck Society;
http://link.springer.com/article/10.1007%2Fs10058-015-0184-7 (Any fulltext)
Güth, W., Levínský, R., Pull, K., & Weisel, O. (2016). Tournaments and piece rates revisited: a theoretical and experimental study of output-dependent prize tournaments. Review of Economic Design, 20(1), 69-88.