From e21a6085524055694a1fc088c5e89beee9cd8ae9 Mon Sep 17 00:00:00 2001
From: Rong Ou <rong.ou@gmail.com>
Date: Tue, 19 May 2020 19:46:16 -0700
Subject: [PATCH] add pointers to the gpu external memory paper (#5684)

---
 doc/gpu/index.rst                 | 2 ++
 doc/tutorials/external_memory.rst | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/doc/gpu/index.rst b/doc/gpu/index.rst
index c9e8391e4..3727dcddb 100644
--- a/doc/gpu/index.rst
+++ b/doc/gpu/index.rst
@@ -227,6 +227,8 @@ References
 
 `Nvidia Parallel Forall: Gradient Boosting, Decision Trees and XGBoost with CUDA <https://devblogs.nvidia.com/parallelforall/gradient-boosting-decision-trees-xgboost-cuda/>`_
 
+`Out-of-Core GPU Gradient Boosting <https://arxiv.org/abs/2005.09148>`_
+
 Contributors
 ============
 Many thanks to the following contributors (alphabetical order):
diff --git a/doc/tutorials/external_memory.rst b/doc/tutorials/external_memory.rst
index 03a7c8c78..1cdbe2486 100644
--- a/doc/tutorials/external_memory.rst
+++ b/doc/tutorials/external_memory.rst
@@ -52,6 +52,8 @@ data to further reduce GPU memory usage:
     'sampling_method': 'gradient_based',
   }
 
+For more information, see `this paper <https://arxiv.org/abs/2005.09148>`_.
+
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