diff --git a/src/eva2/server/go/operators/crossover/CrossoverESArithmetical.java b/src/eva2/server/go/operators/crossover/CrossoverESArithmetical.java
index 105577af..5a6858c5 100644
--- a/src/eva2/server/go/operators/crossover/CrossoverESArithmetical.java
+++ b/src/eva2/server/go/operators/crossover/CrossoverESArithmetical.java
@@ -7,6 +7,11 @@ import eva2.server.go.problems.InterfaceOptimizationProblem;
 import eva2.tools.math.RNG;
 
 /**
+ * The children are randomized intermediate combinations of the parents,
+ * namely c[i]=Sum_j (r_i * p_ji)
+ * where r_i are uniform random numbers normed to the sum of one and
+ * p_ji is the i-th component of parent j.
+ *  
  * Created by IntelliJ IDEA.
  * User: streiche
  * Date: 25.07.2003
@@ -75,7 +80,7 @@ public class CrossoverESArithmetical implements InterfaceCrossover, java.io.Seri
             // write the result back
             for (int i = 0; i < result.length; i++) ((InterfaceESIndividual)result[i]).SetDGenotype(children[i]);
         }
-        //in case the crossover was successfull lets give the mutation operators a chance to mate the strategy parameters
+        //in case the crossover was successful lets give the mutation operators a chance to mate the strategy parameters
         for (int i = 0; i < result.length; i++) result[i].getMutationOperator().crossoverOnStrategyParameters(indy1, partners);
         //for (int i = 0; i < result.length; i++) System.out.println("After Crossover: " +result[i].getSolutionRepresentationFor());
         return result;
diff --git a/src/eva2/server/go/operators/crossover/CrossoverESFlat.java b/src/eva2/server/go/operators/crossover/CrossoverESFlat.java
index 390e9f1b..da577c6c 100644
--- a/src/eva2/server/go/operators/crossover/CrossoverESFlat.java
+++ b/src/eva2/server/go/operators/crossover/CrossoverESFlat.java
@@ -1,9 +1,6 @@
 package eva2.server.go.operators.crossover;
 
 
-import javax.swing.*;
-
-import eva2.gui.Plot;
 import eva2.server.go.individuals.AbstractEAIndividual;
 import eva2.server.go.individuals.InterfaceESIndividual;
 import eva2.server.go.populations.Population;
@@ -11,6 +8,13 @@ import eva2.server.go.problems.InterfaceOptimizationProblem;
 import eva2.tools.math.RNG;
 
 /**
+ * The flat crossover inits values randomly within the extreme values of
+ * all parents, namely
+ * c[i]=rand(min_j(p_ij), max_j(p_ij)).
+ * 
+ * where c[i] is the i-th child component and p_ij is the i-th component
+ * of parent j.
+ * 
  * Created by IntelliJ IDEA.
  * User: streiche
  * Date: 02.12.2003