@article{Lopez_1977,
title={Bounds on the π0π0 amplitude},
volume={118},
ISSN={0550-3213},
url={http://dx.doi.org/10.1016/0550-3213(77)90237-1},
DOI={10.1016/0550-3213(77)90237-1},
number={5},
journal={Nuclear Physics B},
publisher={Elsevier BV},
author={Lopez,
C. and Mennessier,
G.},
year={1977},
month=feb,
pages={426–444} }