diff --git a/jaxpm/pm.py b/jaxpm/pm.py
index 32a9691..7aac781 100644
--- a/jaxpm/pm.py
+++ b/jaxpm/pm.py
@@ -74,7 +74,7 @@ def make_ode_fn(mesh_shape):
 
 def pgd_correction(pos, params):
     """
-    improve the short-range interactions of PM-Nbody simulations with potential gradient descent method
+    improve the short-range interactions of PM-Nbody simulations with potential gradient descent method, based on https://arxiv.org/abs/1804.00671
     """
     kvec = fftk(mesh_shape)