@book{Simon, author = {Simon, E.}, title = {Aufbau im Untergang, T{\"u}bingen (J. C. B. Mohr) 1959.}, language = {de} } @book{Simon, author = {Simon, E.}, title = {Br{\"u}cken, Heidelberg (Verlag Lambert Schneider) 1965.}, language = {de} }