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2.Wei Liu, Jane Davidson, Raghu Raman, and Susan Mantell, “ Thermal and Economic Analysis of Plastic Heat Exchangers for Solar Water Heating” , Department of Mechanical Engineering , University of Minnesota, 111 Church St., S.E. Minneapolis, MN 55455.
3.Jane Davidson, Derek Oberreit, Wei Liu and Susan Mantell , “Are Plastic Heat Exchangers Feaslble For Solar Water Heaters” , Department of Mechanical Engineering , University of Minnesota , 111 Church St., S.E. Minneapolis, MN 55455 , April 11-15, 1999 .