Doctoral research

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY The summary of this article is not available.

SUMMARY This article is available only in Slovak without a summary.