Results on ππ - interaction in the reaction π⁻p → π⁰π⁰n at 8 GeV/c Apel, W. D.; Auslaender, J. S.; Mueller, H.; Sigurdsson, G.; Staudenmaier, H. M.; Stier, U.; Bertolucci, E.; Mannelli, I.; Pierazzini, G.; Rehak, P.; Scribano, A.; Sergiampietri, F.; Vincelli, M. L. 1972. Physics Letters, XVI. International Conference on High-Energy Physics, Chicago, September 6-13, 1972, 41B, 542–46