diff --git a/potentials/Cu_u6.eam b/potentials/Cu_u6.eam
index e5e810bc53..278c84dc1d 100644
--- a/potentials/Cu_u6.eam
+++ b/potentials/Cu_u6.eam
@@ -1,4 +1,4 @@
-Cu functions (universal 4)
+Cu functions (universal 4) - JB Adams et al J. Mater. Res., 4(1), 102 (1989)
    29     63.550         3.6150    FCC
   500  5.0100200400801306e-04  500  1.0000000000000009e-02  4.9499999999999886e+00
   0.                     -3.1589719908208558e-01 -5.2405175291223927e-01 -6.9885553834123115e-01 -8.5420409172727574e-01