add a reference

Author: mjlosch

doc/manual_references.bib

@@ -673,7 +673,15 @@ @Article{stevens:90
   pages =  {103--133}
 }
 
-
+@Article{sem76,
+  author =	 {Semtner, Jr., Albert J.},
+  title =	 {A model for the thermodynamic growth of sea ice in
+                  numerical investigations of climate},
+  journal =	 jpo,
+  year =	 1976,
+  volume =	 6,
+  pages =	 {379--389}
+}
 
 @Article{Stommel66,
  author   = {H. Stommel},