diff --git a/README.md b/README.md
index bc23a22..71d0664 100644
--- a/README.md
+++ b/README.md
@@ -47,7 +47,7 @@ for caching the computed 3j and 6j symbols.
 ## Todo
 *   Wigner 9-j symbols, as explained in [1] and based on
 
-    [3] [L. Wei, New formula for 9-j symbols and their direct calculation, Computers in Physics, 12 (1998), 632–634.(ftp://gravity.physics.uwa.edu.au/pub/Clebsch-Gordan/Papers/Wei9j.pdf)
+    [3] [L. Wei, New formula for 9-j symbols and their direct calculation, Computers in Physics, 12 (1998), 632–634.](ftp://gravity.physics.uwa.edu.au/pub/Clebsch-Gordan/Papers/Wei9j.pdf)
 
 *   Convenient syntax to get the exact results in the `√(r) * s` format, but in such a way that it can be used by
     the Julia type system and can be converted afterwards.