text: Since then , Ipswich Town remain undefeated at Portman Road in all European competitions , a total of 31 matches spanning 40 years , a record until it was surpassed by AZ Alkmaar in December 2007 .
simplified: Since then , Ipswich Town remain undefeated at Portman Road in all European competitions . They have played a total of 31 matches over 40 years , a world record until it was beaten by AZ Alkmaar in December 2007 .