Related papers: Reply to Wang's comment

This paper has been withdrawn.

This paper has been withdrawn by the author because eq.(4) and those subsequent are incorrect.

The paper has been withdrawn.

This paper has been withdrawn by the authors because the results obtained have been reported earlier by other authors.

This paper has been withdrawn by the authors.

The article has been withdrawn - the proof of the final corollary turned out to rely on an unproven statement. If the authors will manage to repair the argument, resubmission will be made.

This paper is cancelled

The paper has been withdrawn by the authors

The paper is being withdrawn. A new submission will follow.

This paper has been withdrawn. (Reason) Its contents have been entirely superseded by the contents of the articles arXiv:0809.3444 and arXiv:0705.3070. There is no profitable reason to keep it alive. No material on it is however wrong.

This paper has been withdrawn by the author.

The paper has been withdrawn.

This paper has been withdrawn by the author due to an error.

This paper has been withdrawn by the author. The result is already known.

This paper has been withdrawn.

This paper has been withdrawn by the author.

This paper has been withdrawn.

This paper has been withdrawn by author.

The paper has been withdrawn by the author.

The calculations of Guang-Wen Ma's recent Letter [Phys.Lett. A239, (1998) 209] contain an easily detectable error which makes his conclusions irrelevant.