Multiple Periodic Solutions of Differential Delay Equations with 2<i>k</i>-1 Lags

Lin LI, Hua-fei SUN, Wei-gao GE

Acta Mathematicae Applicatae Sinica(English Series) . 2020, (2): 390 -400 . DOI: 10.1007/s10255-020-0946-z