diff --git a/src/sgd.h b/src/sgd.h
index dbf14552..65b3c6f1 100644
--- a/src/sgd.h
+++ b/src/sgd.h
@@ -22,23 +22,24 @@ class Sgd {
     float eta_;
 };
 
+// @TODO: Add serialization for historic gradients and parameters
 class Adagrad {
   public:
     Adagrad(float eta=0.01, float eps=10e-8)
     : eta_(eta), eps_(eps) {}
     
     void operator()(ExpressionGraph& graph, int batchSize) {
-        graph.backprop(batchSize);
+      graph.backprop(batchSize);
       
-      if(history_.size() < graph.params().size())
+      if(gt_.size() < graph.params().size())
         for(auto& param : graph.params())
-          history_.emplace_back(Tensor(param.grad().shape(), 0));
+          gt_.emplace_back(Tensor(param.grad().shape(), 0));
       
-      auto it = history_.begin();
+      auto gtIt = gt_.begin();
       for(auto& param : graph.params()) {    
-        Element(_1 += _2 * _2, *it, param.grad());
+        Element(_1 += _2 * _2, *gtIt, param.grad());
         Element(_1 -= eta_ / (Sqrt(_2) + eps_) * _3,
-                param.val(), *it, param.grad());
+                param.val(), *gtIt, param.grad());
         it++;
       }
     }
@@ -46,9 +47,10 @@ class Adagrad {
   private:
     float eta_;
     float eps_;
-    std::vector<Tensor> history_;
+    std::vector<Tensor> gt_;
 };
 
+// @TODO: Add serialization for historic gradients and parameters
 class Adam {
   public:
     Adam(float eta=0.01, float beta1=0.999, float beta2=0.999, float eps=10e-8)