Endogamy study:
http://eclectic.anthrosciences.org/~drwhite/T&S/BrudnerW...

Some intermarrying still continued in Milwaukee with a Schnabl (whose son was a second cousin of mine) and a Millonig, who happened to be a boarder and afterwards married the daughter of his landlord. They all lived together on 28th Street, just off Hopkins across the street from the large AO Smith factory (32 or so city blocks). The Millonigs in Achomitz/Feistritz seemed to have lots of kids...