So here's some sites I found:
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WDV-4K716F8-5&_user=501045&_coverDate=09%2F30%2F2006&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000022659&_version=1&_urlVersion=0&_userid=501045&md5=37c6fa35d83df8a2b78de95655843f0e
http://www.blackwell-synergy.com/action/showPdf?submitPDF=Full+Text+PDF+%28178+KB%29&doi=10.1111%2Fj.1095-8649.2006.01161.x
I can summarize them during class tomorrow.
Elli