Upper and lower solution method for fourth-order four-point boundary value problems
2009 ◽
Vol 223
(2)
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pp. 543-551
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2006 ◽
Vol 196
(2)
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pp. 387-393
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2009 ◽
Vol 215
(6)
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pp. 2243-2247
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2002 ◽
Vol 147
(1)
◽
pp. 41-52
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2011 ◽
Vol 285
◽
pp. 012016
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