http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V8K-512K1KY-1&_user=10&_coverDate=01/31/2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=ae336445c13e1f5172d6f65d0c420f4d&searchtype=a
15 years ago
85 upvotes – 140 comments