update readings

Author: lazyprogrammer

ann_class2/extra_reading.txt

@@ -12,4 +12,10 @@ https://static.googleusercontent.com/media/research.google.com/en//archive/large
 
 Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shift
 Sergey Ioffe, Christian Szegedy
-https://arxiv.org/abs/1502.03167
+https://arxiv.org/abs/1502.03167
+
+Xavier (Glorot) Normal Initializer
+http://jmlr.org/proceedings/papers/v9/glorot10a/glorot10a.pdf
+
+He Normal Initializer
+http://arxiv.org/abs/1502.01852