Reitan, Clayton Harold. 1971. ?An Assessment Of The Role Of Volcanic Dust In Determining Modern Changes In The Temperature Of The Northern Hemisphere?. University of Wisconsin. http://ezproxy.library.arizona.edu/login?url=http://proquest.umi.com/pqdweb?did=756913801&sid=8&Fmt=1&clientId=43922&RQT=309&VName=PQD.