1. Particle Data Group, S. Eidelman et al. , Phys. Lett. B 592 (2004) 1
2. For recent reviews of experimental results and theoretical models see: http://www.rcnp.osaka-u.ac.jp/~hyodo/ research/Thetapub.html; A.R. Dzierba, C.A. Meyer, A.P. Szczepaniak, Reviewing the evidence for pentaquarks, Proc. 1st Meeting of the APS Topical Group on Hadronic Physics, Batavia, Illinois, October 2004 and hep-ex/0412077
3. NA49 Collaboration, C. Alt et al. , Phys. Rev. Lett. 92 (2004) 042003 and private communication
4. ALEPH Collaboration, S. Schael et al. , Phys. Lett. B 599 (2004) 1
5. BaBar Collaboration, B. Aubert et al. , SLAC-PUB-10992 and hep-ex/0502004, submitted to Phys. Rev. Lett.; D.R. Muller, private communication