By means of the Krasnoselskii fixed piont theorem, periodic solutions are found for a neutral type delay differential system of the form \[ x^{\prime }\left( t\right) +cx^{\prime }\left( t-\tau \right) =A\left( t,x(t)\right) x\left( t\right) +f\left( t,x\left( t-r_{1}\left( t\right) \right) ,\dots ,x\left( t-r_{k}\left( t\right) \right) \right) . \]
@article{107976, author = {Cheng-Jun Guo and Gen Qiang Wang and Sui-Sun Cheng}, title = {Periodic solutions for a neutral functional differential equation with multiple variable lags}, journal = {Archivum Mathematicum}, volume = {042}, year = {2006}, pages = {1-10}, zbl = {1164.34517}, mrnumber = {2227107}, language = {en}, url = {http://dml.mathdoc.fr/item/107976} }
Guo, Cheng-Jun; Wang, Gen Qiang; Cheng, Sui-Sun. Periodic solutions for a neutral functional differential equation with multiple variable lags. Archivum Mathematicum, Tome 042 (2006) pp. 1-10. http://gdmltest.u-ga.fr/item/107976/
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