diff --git a/moeo/src/algo/moeoSPEA2.h b/moeo/src/algo/moeoSPEA2.h
index a6416ecc2..8b419b5f5 100644
--- a/moeo/src/algo/moeoSPEA2.h
+++ b/moeo/src/algo/moeoSPEA2.h
@@ -255,7 +255,7 @@ protected:
     eoQuadCloneOp < MOEOT > defaultQuadOp;
     /** an object for genetic operators (used as default) */
     eoSGAGenOp < MOEOT > defaultSGAGenOp;
-    /** fitness assignment used in NSGA-II */
+    /** fitness assignment used in SPEA2 */
     moeoDominanceCountRankingFitnessAssignment < MOEOT > fitnessAssignment;
     /** general breeder */
     eoGeneralBreeder < MOEOT > genBreed;
@@ -265,7 +265,7 @@ protected:
     eoSelectTransform <MOEOT> selectTransform;
     /** breeder */
     eoBreed < MOEOT > & breed;
-    /** diversity assignment used in NSGA-II */
+    /** diversity assignment used in SPEA2 */
     moeoNearestNeighborDiversityAssignment  < MOEOT > diversityAssignment;
     /** elitist replacement */
     moeoGenerationalReplacement < MOEOT > replace;
diff --git a/moeo/src/diversity/moeoFrontByFrontCrowdingDiversityAssignment.h b/moeo/src/diversity/moeoFrontByFrontCrowdingDiversityAssignment.h
index 7ab4e0067..c4909d504 100644
--- a/moeo/src/diversity/moeoFrontByFrontCrowdingDiversityAssignment.h
+++ b/moeo/src/diversity/moeoFrontByFrontCrowdingDiversityAssignment.h
@@ -44,9 +44,9 @@
 
 
 /**
- * Diversity assignment sheme based on crowding proposed in:
+ * Diversity assignment scheme based on crowding proposed in:
  * K. Deb, A. Pratap, S. Agarwal, T. Meyarivan, "A Fast and Elitist Multi-Objective Genetic Algorithm: NSGA-II", IEEE Transactions on Evolutionary Computation, vol. 6, no. 2 (2002).
- * Tis strategy assigns diversity values FRONT BY FRONT. It is, for instance, used in NSGA-II.
+ * This strategy assigns diversity values FRONT BY FRONT. It is, for instance, used in NSGA-II.
  */
 template < class MOEOT >
 class moeoFrontByFrontCrowdingDiversityAssignment : public moeoCrowdingDiversityAssignment < MOEOT >
diff --git a/moeo/src/diversity/moeoNearestNeighborDiversityAssignment.h b/moeo/src/diversity/moeoNearestNeighborDiversityAssignment.h
index 8571ed475..5b5680eef 100644
--- a/moeo/src/diversity/moeoNearestNeighborDiversityAssignment.h
+++ b/moeo/src/diversity/moeoNearestNeighborDiversityAssignment.h
@@ -46,7 +46,14 @@
 #include <archive/moeoArchive.h>
 
 /**
- * moeoNearestNeighborDiversityAssignment is a moeoDiversityAssignment using distance between individuals to assign diversity.
+ * moeoNearestNeighborDiversityAssignment is a moeoDiversityAssignment
+ * using distance between individuals to assign diversity. Proposed in:
+ * E. Zitzler, M. Laumanns, and L. Thiele. SPEA2: Improving the
+ * Strength Pareto Evolutionary Algorithm. Technical Report 103,
+ * Computer Engineering and Networks Laboratory (TIK), ETH Zurich,
+ * Zurich, Switzerland, 2001.
+
+ * It is used in moeoSPEA2.
  */
 template < class MOEOT >
 class moeoNearestNeighborDiversityAssignment : public moeoDiversityAssignment < MOEOT >