@article{Lopez_1975,
title={A lower bound to the π0π0 S-wave scattering length},
volume={88},
ISSN={0550-3213},
url={http://dx.doi.org/10.1016/0550-3213(75)90287-4},
DOI={10.1016/0550-3213(75)90287-4},
number={2},
journal={Nuclear Physics B},
publisher={Elsevier BV},
author={Lopez,
C.},
year={1975},
month=mar,
pages={358–364} }