diff --git a/docs/article/paper.bib b/docs/article/paper.bib
index 53c066e1..4449c0eb 100644
--- a/docs/article/paper.bib
+++ b/docs/article/paper.bib
@@ -88,6 +88,18 @@ @article{ding2003mathematical
   doi={10.1016/S1050-6411(03)00102-0},
 }
 
+@article{ding2007mathematical,
+  title={Mathematical model that predicts the force--intensity and force--frequency relationships after spinal cord injuries},
+  author={Ding, Jun and Chou, Li-Wei and Kesar, Trisha M and Lee, Samuel CK and Johnston, Therese E and Wexler, Anthony S and Binder-Macleod, Stuart A},
+  journal={Muscle \& Nerve: Official Journal of the American Association of Electrodiagnostic Medicine},
+  volume={36},
+  number={2},
+  pages={214--222},
+  year={2007},
+  publisher={Wiley Online Library},
+    doi={10.1002/mus.20806},
+}
+
 @article{michaud2022bioptim,
   title={Bioptim, a python framework for musculoskeletal optimal control in biomechanics},
   author={Michaud, Benjamin and Bailly, Fran{\c{c}}ois and Charbonneau, Eve and Ceglia, Amedeo and Sanchez, L{\'e}a and Begon, Mickael},