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								Bert L Hartnell
							
              						
 
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								Douglas F Rall
							
              						
 
									
			
																												
							
									
				
										Keywords:
				
				
																		maximal independent set, 													well-covered, 													Cartesian product															
			
			
										
					
Abstract
					A graph is well-covered if every maximal independent set has the same cardinality, namely the vertex independence number.  We answer a question of Topp and Volkmann and prove that if the Cartesian product of two graphs is well-covered, then at least one of them must be well-covered.