1. OPAL Collaboration, G. Abbiendi et al., Photonic events with missing energy in $$e^+e^-$$ e + e - collisions at $$\sqrt{s}$$ s = 189 GeV. Eur. Phys. J. C 18, 253–272 (2000). [ hep-ex/0005002 ]
2. ALEPH Collaboration, A. Heister et al., Single photon and multiphoton production in $$e^{+} e^{-}$$ e + e - collisions at $$\sqrt{s}$$ s up to 209 GeV. Eur. Phys. J. C 28, 1–13 (2003)
3. L3 Collaboration, P. Achard et al., Single photon and multiphoton events with missing energy in $$e^{+} e^{-}$$ e + e - collisions at LEP, Phys. Lett. B 587, 16–32 (2004) [ hep-ex/0402002 ]
4. DELPHI Collaboration, J. Abdallah et al., Photon events with missing energy in $$e^+e^-$$ e + e - collisions at $$\sqrt{s}$$ s = 130 GeV to 209 GeV. Eur. Phys. J. C 38, 395–411 (2005). [ hep-ex/0406019 ]
5. CDF Collaboration, D. Acosta et al., Limits on extra dimensions and new particle production in the exclusive photon and missing energy signature in $$p\bar{p}$$ p p ¯ collisions at $$\sqrt{s} = 1.8$$ s = 1.8 TeV. Phys. Rev. Lett. 89, 281801 (2002). [ hep-ex/0205057 ]