Related papers: Withrawn paper

This paper has been retracted.

This paper has been withdrawn while the author verifies the literature.

Withdrawn due to extensions and submission as another paper.

This paper was withdrawn by the author because severe errors were discovered.

This paper has been withdrawn by the author due to a crucial sign error in equation 1

This paper has been withdrawn by the author.

This paper has been withdrawn.

This paper has been withdrawn by the authors, due to a mistake pointed out by Lenny Ng and Josh Sabloff.

This paper is withdrawn because the results in the paper are included in a paper to be published in Mathematical and Computer Modelling.

This paper has been withdrawn by the author due to a sheaf-theoretic error, in the end of the proof of the main theorem.

This paper has been withdrawn due to its publication

This paper has been withdrawn by the author due to a mistake in the proof of the main theorem.

This paper has been withdrawn by the author due to unspecified problems.

This paper has been withdrawn by the authors.

This paper has been withdrawn by the author due to crucial errors.

This paper has been withdrawn by the authors; the main conclusion is incorrect, as some of the crucial calculations were not properly converged.

This paper was withdrawn by the author.

This paper has been withdrawn by the author.

This paper has been withdrawn by the author due to errors and bad formalization.

This paper has been withdrawn