On the existence of positive solutions for systems of differential equations with a distributed delay
2012 ◽
Vol 63
(7)
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pp. 1256-1265
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1974 ◽
Vol 72
(2)
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pp. 109-127
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2013 ◽
Vol 16
(4)
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2005 ◽
Vol 184
(2)
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pp. 131-138
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