[gegl] nohalo: add reference to C. Racette's work

[Nicolas Robidoux <nrobidoux src gnome org>]

commit 8ead5386d4fd45e68b8beda35d771ea0829b260e
Author: Nicolas Robidoux <nrobidoux git gnome org>
Date:   Sat Jan 5 17:15:17 2013 -0500

    nohalo: add reference to C. Racette's work

 gegl/buffer/gegl-sampler-nohalo.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gegl/buffer/gegl-sampler-nohalo.c b/gegl/buffer/gegl-sampler-nohalo.c
index b488ea0..b6d8f38 100644
--- a/gegl/buffer/gegl-sampler-nohalo.c
+++ b/gegl/buffer/gegl-sampler-nohalo.c
@@ -60,6 +60,12 @@
  *   K.  CPU, SMP and GPU implementations of Nohalo level 1, a fast
  *   co-convex antialiasing image resampler.  In Proceedings of
  *   C3S2E. 2009, 185-195.
+ *
+ * and
+ *
+ *   Racette, C. Numerical Analysis of Diagonal-Preserving,
+ *   Ripple-Minimizing and Low-Pass Image Resampling Methods. CoRR.
+ *   2012. http://arxiv.org/abs/1204.4734.
  */
 
 /*