diff --git a/Electric/ConnectionTriangleStar.cs b/Electric/ConnectionTriangleStar.cs
index 96a2b4d..952296e 100644
--- a/Electric/ConnectionTriangleStar.cs
+++ b/Electric/ConnectionTriangleStar.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Calculations.Electric
+namespace Calculations.Electric
 {
     /// <summary>
     /// Calculations parameters if winding of synchronous/asynchronous motor/generator/transformer change connection between star and triangle
diff --git a/Electric/MaterialTemperatureResistivityCoefficient.cs b/Electric/MaterialTemperatureResistivityCoefficient.cs
index a3e3bc6..7bde331 100644
--- a/Electric/MaterialTemperatureResistivityCoefficient.cs
+++ b/Electric/MaterialTemperatureResistivityCoefficient.cs
@@ -1,11 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Net.NetworkInformation;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Calculations.Electric
+namespace Calculations.Electric
 {
 	/// <summary>
 	/// Constants of Temperature Coeficients of Resistivity
diff --git a/Electric/ResistanceTemperatureChange.cs b/Electric/ResistanceTemperatureChange.cs
index d4fd05c..4dafa2c 100644
--- a/Electric/ResistanceTemperatureChange.cs
+++ b/Electric/ResistanceTemperatureChange.cs
@@ -1,10 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Calculations.Electric
+namespace Calculations.Electric
 {
 	/// <summary>
 	/// Calculations of temperature versus change in conductor resistance and vice versa