Theorie Referenz zu modale Masse hinzugefügt

sections/References.bib

@@ -63,6 +63,18 @@
   edition = {},
   gender={sm},
 }
+%Ray W. Clough and Joseph Penzien. Dynamics of Structures. McGraw-Hill. New York. p. 559. 1975.
+@BOOK{clough03,
+  author = {Clough, Ray W. and Penzien, Joseph},
+  title= {Dynamics of Structures},
+  subtitle= {},
+  publisher = {Computers \& Structures, Inc.},
+  year = {2003},
+  address = {Berkeley},
+  edition = {3},
+  pages = {626 -- 627},
+  gender={pm},
+}
 @BOOK{ermanni04,
   author = {Ermanni, Paolo and Kress, Gerald},
   title= {Leichtbau III},