diff --git a/pybamm/models/submodels/thermal/lumped.py b/pybamm/models/submodels/thermal/lumped.py
index 5b266f1a0a..9b762b17fc 100644
--- a/pybamm/models/submodels/thermal/lumped.py
+++ b/pybamm/models/submodels/thermal/lumped.py
@@ -7,7 +7,7 @@
 
 
 class Lumped(BaseThermal):
-    """Class for lumped thermal submodel
+    """Class for lumped thermal submodel. For more information see [1]_.
 
     Parameters
     ----------
@@ -19,6 +19,11 @@ class Lumped(BaseThermal):
         The geometry for the lumped thermal submodel. Can be "arbitrary" (default) or
         pouch.
 
+    References
+    ----------
+    .. [1] R Timms, SG Marquis, V Sulzer, CP Please and SJ Chapman. “Asymptotic
+           Reduction of a Lithium-ion Pouch Cell Model”. In preparation, 2020.
+
     **Extends:** :class:`pybamm.thermal.BaseThermal`
     """
 
diff --git a/pybamm/models/submodels/thermal/x_full.py b/pybamm/models/submodels/thermal/x_full.py
index b7efba9169..8beb3fbcea 100644
--- a/pybamm/models/submodels/thermal/x_full.py
+++ b/pybamm/models/submodels/thermal/x_full.py
@@ -12,17 +12,24 @@ class OneDimensionalX(BaseThermal):
     in the current collectors, so that the contribution to the Ohmic heating
     from the current collectors is zero and the boundary conditions are applied
     at the edges of the electrodes (at x=0 and x=1, in non-dimensional coordinates).
+    For more information see [1]_.
 
     Parameters
     ----------
     param : parameter class
         The parameters to use for this submodel
 
+    References
+    ----------
+    .. [1] R Timms, SG Marquis, V Sulzer, CP Please and SJ Chapman. “Asymptotic
+           Reduction of a Lithium-ion Pouch Cell Model”. In preparation, 2020.
+
     **Extends:** :class:`pybamm.thermal.BaseThermal`
     """
 
     def __init__(self, param):
         super().__init__(param)
+        pybamm.citations.register("Timms2020")
 
     def get_fundamental_variables(self):
         T_n = pybamm.standard_variables.T_n
diff --git a/tests/unit/test_citations.py b/tests/unit/test_citations.py
index dc8299e5ef..f870e3cab9 100644
--- a/tests/unit/test_citations.py
+++ b/tests/unit/test_citations.py
@@ -107,6 +107,16 @@ def test_timms_2020(self):
         pybamm.thermal.pouch_cell.CurrentCollector2D(param=None)
         self.assertIn("Timms2020", citations._papers_to_cite)
 
+        citations._reset()
+        self.assertNotIn("Timms2020", citations._papers_to_cite)
+        pybamm.thermal.Lumped(param=None)
+        self.assertIn("Timms2020", citations._papers_to_cite)
+
+        citations._reset()
+        self.assertNotIn("Timms2020", citations._papers_to_cite)
+        pybamm.thermal.OneDimensionalX(param=None)
+        self.assertIn("Timms2020", citations._papers_to_cite)
+
     def test_subramanian_2005(self):
         # Test that calling relevant bits of code adds the right paper to citations
         citations = pybamm.citations