link to Kahan paper

Author: skirpichev

peps/pep-0812.rst

@@ -191,7 +191,8 @@ by the PEP:
     lest the sign of zero be rendered uninformative; the same goes for
     combinations of pure imaginary quantities with complex variables.
 
-    -- Kahan, W: Branch cuts for complex elementary functions.
+    -- Kahan, W: `Branch cuts for complex elementary functions
+    <https://people.freebsd.org/~das/kahan86branch.pdf>`_.
 
 
 The complex facility should be simple