Update references.

docs/references.rst

@@ -3,6 +3,18 @@ References
 **********
 
 .. [Lho16] Lhotka, L. *JSON Encoding of Data Modeled with YANG.*
-	   `draft-ietf-netmod-yang-json`__, IETF, 2016.
+	   `draft-ietf-netmod-yang-json`__, Internet Engineering Task
+	   Force, 2016.
 
 __ https://tools.ietf.org/html/draft-ietf-netmod-yang-json
+
+.. [PEP484] van Rossum, G.; Lehtosalo, J.; Langa, Ł. *Type Hints.*
+	    `PEP 484`__, Python Software Foundation, 2014.
+
+__ https://www.python.org/dev/peps/pep-0484
+
+.. [RFC3986] Berners-Lee, T.; Fielding, R.; Masinter, L. *Uniform
+	     Resource Identifier (URI): Generic Syntax*. `RFC 3986`__,
+	     Internet Engineering Task Force, 2005.
+
+__ https://tools.ietf.org/html/rfc3986