Update README.md

Shuo Jiang · web-flow · commit 4708c334f591 · 2019-04-11T17:03:04.000-04:00
diff --git a/README.md b/README.md
@@ -1,3 +1,5 @@
 # Incremental-Gaussian-Process-Regression-SGPR
 
-Just run 'IGPR_test.py', and see the reconstruction result. I will make a documentation soon.
+Just run 'IGPR_test.py', and see the reconstruction result. I will make a documentation soon. 
+Read this book: "Gaussian Processes for Machine Learning"  
+Read this paper: "Incremental Sparsification for Real-time Online Model Learning"
