updated bulk tutorial

Author: simongravelle

docs/sphinx/source/journal-article.bib

@@ -257,6 +257,14 @@ @book{van1995python
   publisher={Centrum voor Wiskunde en Informatica Amsterdam}
 } 
 
+@misc{grace,
+  author       = {{Grace Development Team}},
+  title        = {{Grace: A WYSIWYG 2D plotting tool for the X Window System}},
+  year         = {2015},
+  howpublished = {\url{http://plasma-gate.weizmann.ac.il/Grace/}},
+  note         = {Version 5.1.25}
+}
+
 @article{humphrey1996vmd,
   title={{{VMD}}: visual molecular dynamics},
   author={Humphrey, William and Dalke, Andrew and Schulten, Klaus},