And a few more links: http://www.springerlink.com/content/tyy00w31extww8p1/ http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V09-3Y4510K-1B&_user=10&_coverDate=06%2F30%2F1995&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1263077754&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=c9834a5a69604f23126bf53e06e6655c
And a few more links: www.springerlin k.com/content/ tyy00w31extww8p 1/ www.sciencedire ct.com/ science? _ob=ArticleURL& _udi=B6V09- 3Y4510K- 1B&_user= 10&_coverDate= 06%2F30% 2F1995& _rdoc=1& _fmt=high& _orig=search& _sort=d& _docanchor= &view=c& _searchStrId= 1263077754& _rerunOrigin= scholar. google& _acct=C00005022 1&_version= 1&_urlVersion= 0&_userid= 10&md5= c9834a5a69604f2 3126bf53e06e665 5c
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