@article{article67fde21b,
title   = {Periodic positive solutions of superlinear delay equations via topological degree},
author = {Amster, Pablo and Benevieri, Pierluigi and Haddad, Julián},
year = {2021},
doi = {10.1098/rsta.2019.0373},
journal   = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}
}