H. Braun, H.U. Martyn, O. Erriquez, F. Romano, D. Bertrand, et al.. An experimental determination of the parameters describing the $K^+ \rightarrow \pi^+ \pi^{\circ} \pi^{\circ}$ decay matrix element.
Il Nuovo Cimento, 1976, 17, pp.521-523.
⟨in2p3-00010454⟩