diff --git a/doc/source/models/model_potentials.ipynb b/doc/source/models/model_potentials.ipynb
index b63c98e988e80437f76db9ae1a3e1895b2ab5426..b5e2753c1d2ef02671d18e13ce29e3a4479daf31 100644
--- a/doc/source/models/model_potentials.ipynb
+++ b/doc/source/models/model_potentials.ipynb
@@ -38,7 +38,14 @@
     "         \\end{array}\\right.        \n",
     "$\n",
     "\n",
-    "from which an EOS can be developed by correlating results from molecular simulation."
+    "from which an EOS can be developed by correlating results from molecular simulation. The EOS is from:\n",
+    "\n",
+    " Rodolfo Espíndola-Heredia, Fernando del Río and Anatol Malijevsky\n",
+    " Optimized equation of the state of the\n",
+    " square-well fluid of variable range based on\n",
+    " a fourth-order free-energy expansion\n",
+    " J. Chem. Phys. 130, 024509 (2009); https://doi.org/10.1063/1.3054361\n",
+    " "
    ]
   },
   {