Existence of periodic solutions for second-order differential equations with singularities and the strong force condition
2006 ◽
Vol 317
(1)
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pp. 1-13
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1993 ◽
Vol 119
(2)
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pp. 439-439
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2005 ◽
Vol 308
(2)
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pp. 393-419
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1988 ◽
Vol 103
(3)
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pp. 765-765
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1943 ◽
Vol 22
(1-4)
◽
pp. 41-48
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