1. J. Lee-Franzini, D.B. Lichtenberg E. Predazzi: Quarkonium, QCD, and the case for a new electron-positron collider. Workshop on Heavy Quarks Factory and Nuclear Physics Facility with Superconducting Linacs, Courmayeur, Italy (1987)
2. J.H. Kuhn, P.M. Zerwas: The toponium scenario, report MPI-PAE/Pth 52/87, Munich (1987)
3. D.B. Lichtenberg. Int. J. Mod. Phys. A 2 (1987) 1669
4. S. Jacobs, M.G. Olsson, C. Suchyta III: Phys. Rev. D33 (1986) 3338
5. Particle Data Group, M. Aguilar-Benitez et al.: Phys. Lett. B 170 (1986) 1