add two new materials and list additional information

src/data/example.json

@@ -71,7 +71,10 @@
     },
     {
       "Type": "Web",
-      "URL": "http://"
+      "Author": "Fa. Honsel",
+      "Title": "Handbuch Knetwerkstoffe",
+      "Year": 2010,
+      "URL": "http://www.eloxal-muenchen.de/downloads/Handbuch_Knetwerkstoffe.pdf"
     }
   ]
 }