http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJX-4BT1RP2-1&_user=10&_coverDate=05%2F31%2F2004&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=df54bfca7fe17072df3ea41064fd36d0http://www.rsc.org/publishing/
journals/OC/article.asp?doi=b110384a
Content provided by Yahoo Answers.