Media type: E-Article Title: High-order variational calculation for the frequency of time-periodic solutions Contributor: Pelster, Axel; Kleinert, Hagen; Schanz, Michael imprint: American Physical Society (APS), 2003 Published in: Physical Review E Language: English DOI: 10.1103/physreve.67.016604 ISSN: 1063-651X; 1095-3787 Origination: Footnote: