Related papers: Lower order eigenvalues of the biharmonic operator

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Submission was withdrawn by authors. arXiv:math/0305140

This paper has been withdrawn by the author due to a mistake in the proof of the main theorem.

This paper has been withdrawn by the author due to an error in section 7. There is a new version: arXiv:1011.3352.

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The paper has been withdrawn

This paper has been withdrawn by the authors due to a gap in the proof of the main result (in 5.3).

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This paper has been withdrawn by the author due to a error in attachment of source file.

This paper has been withdrawn by the author because overcame by arXiv:0910.4694

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This paper has been withdrawn by the authors.

This paper has been withdrawn by the author due to an error estimate in Lemma 3.1.

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This paper has been withdrawn.

This paper has been withdrawn by the author.

Withdrawn by authors.

This paper has been withdrawn by the author.

The paper has been withdrawn

This paper has been withdrawn.