diff --git a/src/Ranger21.py b/src/Ranger21.py
index 6bd2551..ad0502c 100644
--- a/src/Ranger21.py
+++ b/src/Ranger21.py
@@ -1 +1,21 @@
 # Ranger21 - @lessw2020
+
+# core components based on:
+
+# MADGRAD: https://arxiv.org/abs/2101.11075
+
+# warmup:  https://arxiv.org/abs/1910.04209v3
+
+# stable weight decay: https://arxiv.org/abs/2011.11152v3
+
+# Gradient Centralization: https://arxiv.org/abs/2004.01461v2
+
+
+import torch
+import torch.optim
+
+import math
+import collections
+
+import copy
+from torch import linalg as LA