Index: /qipapers.bib
===================================================================
--- /qipapers.bib	(revision 490)
+++ /qipapers.bib	(revision 491)
@@ -20898,2 +20898,10 @@
   author = {Rose, H.}
 }
+@article{Freitag1981,
+  year = {1981},
+  title = {Resolution and contrast of crystalline objects in high-resolution scanning electron microscopy},
+  pages = {407-429},
+  journal = {Optik},
+  volume = {59},
+  author = {Freitag, J. and Rose, H.}
+}