Journal of Differential EquationsVolume 8, Issue 3, November 1970, Pages 523-530Existence of periodic solutions for higher-order differential systems that are not of class DAuthor links open overlay panelJ MawhinShow moreShareCitehttps://doi.org/10.1016/0022-0396(70)90024-0Get rights and contentUnder an Elsevier user licenseopen archivePrevious article in issueNext article in issueRecommended articlesCited by (0)Copyright © 1970 Published by Elsevier Inc.