@article{Auberson_1975,
 title={A tool for extending the analyticity domain of partial-wave amplitudes and the validity of roy-type equations},
 volume={25},
 ISSN={1826-9869},
 url={http://dx.doi.org/10.1007/bf02820858},
 DOI={10.1007/bf02820858},
 number={3},
 journal={Il Nuovo Cimento A},
 publisher={Springer Science and Business Media LLC},
 author={Auberson,
 G. and Epele,
 L.},
 year={1975},
 month=feb,
 pages={453–466} }