"Sa-wave γγ→ππ and f0 (980)→ππ" (2008) Oller, J.A.; Roca, L.; Schat, C.; Luso-American Foundation for Development (FLAD); Calouste Gulbenkian Foundation (FCG); Foundation for Science and Technology (FCT); Center of Physics of the Fundamental Interactions (CFIF); Center of Theoretical Particle Physics (CFTP) Workshop on Scalar Mesons and Related Topics: Honoring Michael D. Scadron's 70th Birthday, SCADRON 2008. 1030:147-152