From 7eab419cabbc6eea70b04121be3762df0315f02c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fran=C3=A7ois=20Boulogne?= <fboulogne sciunto org>
Date: Sat, 12 Jan 2013 12:19:06 +0100
Subject: [PATCH] add references

---
 skimage/draw/_draw.pyx | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/skimage/draw/_draw.pyx b/skimage/draw/_draw.pyx
index 6c50842f..7c77b423 100644
--- a/skimage/draw/_draw.pyx
+++ b/skimage/draw/_draw.pyx
@@ -217,6 +217,12 @@ def circle_perimeter(int cy, int cx, int radius, method='bresenham'):
     is also less distortions when Andres circles are rotated.
     Bresenham method is also known as midpoint circle algorithm.
 
+    References
+    ----------
+    .. [1] J.E. Bresenham, "Algorithm for computer control of a digital
+        plotter", 4 (1965) 25-30.
+    .. [2] E. Andres, "Discrete circles, rings and spheres", 18 (1994) 695-706.
+
     """
 
     cdef list rr = list()