Related papers: On the biharmonic Dirichlet problem: The higher di…

Paper withdrawn by the author.

This paper has been withdrawn

This paper has been withdrawn by the author due to the unsure solution to the Dyson-Schwinger equation.

This paper was withdrawn by arXiv admin due to authors' misrepresentation of identity/affiliation.

This paper has been withdrawn by the author

The paper has been withdrawn by the authors for modification.

This paper has been withdrawn by the author due to an extended and largely modified version of the paper was published in arXiv (see arXiv:0807.3694, Disjoint minimal graphs).

Withdrawn by author - Superseded by arXiv:0910.5106 [math.FA].

This paper has been withdrawn by the author, due an error in claim 1.

This paper has been withdrawn by the authors.

Paper withdrawn, see math-ph/0505072

The paper has been withdraw by authors

The paper is withdrawn. The proof has an error and it requires a different approach.

This paper has been withdrawn by the author due to that the main results and approaches are closedly parallel to the ones in Lie algebra case.

This paper has been withdrawn.

Withdrawn due to extensions and submission as another paper.

This paper has been withdrawn by the author, due to an error in the proof of Theorem 3.8.

This paper has been withdrawn.

This paper has been withdrawn.

Withdrawn; note hep-th/0110236 covers some similar material.