See Census indexes at FamilySearch: Åbenrå County, Denmark Genealogy • FamilySearch
See Census indexes at AKVZ [Arbeitskreis Volkszahl-Register]. This is an ongoing project to index all census records in Schleswig-Holstein.
See census and church record indexes at Danish Family Search
See this link to additional census indexes: https://sites.google.com/site/schleswigholsteincensus/indexes