From d1017f501eb2058908a409818f143d2376863aa6 Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Fri, 2 Nov 2018 00:45:48 -0400
Subject: [PATCH] cone/faces.py: add the missing HilgertHofmannLawson reference
 that I cited.

---
 mjo/cone/faces.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mjo/cone/faces.py b/mjo/cone/faces.py
index 81b8421..70706a8 100644
--- a/mjo/cone/faces.py
+++ b/mjo/cone/faces.py
@@ -143,6 +143,10 @@ def dual_face(K,F):
 
     REFERENCES:
 
+    .. [HilgertHofmannLawson] Joachim Hilgert, Karl Heinrich Hofmann, and Jimmie
+       D. Lawson. Lie groups, convex cones and semigroups. Oxford Mathematical
+       Monographs. Clarendon Press, Oxford, 1989. ISBN 9780198535690.
+
     .. [Tam] Bit-Shun Tam. On the duality operator of a convex cone. Linear
        Algebra and its Applications, 64:33-56, 1985, doi:10.1016/0024-3795(85)
        90265-4.
-- 
2.43.2