1. G. Stricker et al., CDF note 9724 (2009)
2. T. Aaltonen et al. (CDF Collaboration), Phys. Rev. Lett. 101, 202001 (2008)
3. V.M. Abazov et al. (D0 Collaboration), Phys. Rev. Lett. 100, 142002 (2008)
4. A. Djouadi, G. Moreau, F. Richard, R.K. Singh, Phys. Rev. D 82, 071702 (2010)
5. S. Jung, H. Murayama, A. Pierce, J.D. Wells, Phys. Rev. D 81, 015004 (2010)