The listed son Louis Springer is NOT the son of Karl. here is something mixed up.
The son of Karl is Louis de Basse Lotharingie (Ludwig von Niederlothringen) * long bef 989, + abt 1023.
the here listed Louis springer is born 1042 and died 1123. He is called the builder of the Wartburg castle. His father was Ludwig der Bärtige (+ 1056), the main father of the "Ludowinger".
Ludwig der Bärtige, and not his son Louis Springer, married Cecilia von Sangerhausen