"United States Census, 1940," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/KM11-QC8 : accessed 25 Sep 2012), Herman Trauernicht, Muddy Election Precinct, Frontier, Nebraska, United States; citing enumeration district (ED) 32-20, sheet 3A, family 45, NARA digital publication T627, roll 2246.