Updated references to mdplus.pca package

Author: CharlieLaughton

PCA_analysis_of_MD_simulations.ipynb

@@ -19,9 +19,8 @@
     "\n",
     "1. you have a basic understanding of how to use an iPython (Jupyter) notebook.\n",
     "\n",
-    "2. you already have a basic understanding of PCA methods. For much more information about the PCA package used here - **pyPcazip** -, see [here](https://bitbucket.org/ramonbsc/pypcazip) and the paper [Shkurti et al., SoftwareX](http://dx.doi.org/10.1016/j.softx.2016.04.002).\n",
-    "\n",
-    "**pyPcazip** uses a python library called **MDPlus** and that is mainly what you will see in action here. For a guide to the **MDPlus** API, see [here](http://pypcazip.readthedocs.io/en/latest/)."
+    "2. you already have a basic understanding of PCA methods. For much more information about the PCA package used here - **mdplus.pca** -, see [here](https://bitbucket.org/claughton/mdplus) and the paper [Shkurti et al., SoftwareX](http://dx.doi.org/10.1016/j.softx.2016.04.002).\n",
+    "\n"
    ]
   },
   {