diff --git a/helper/ccnb-parser/visitors/ccnb-parser-depth-first-visitor.h b/helper/ccnb-parser/visitors/ccnb-parser-depth-first-visitor.h
index d68b4ad..98c3c96 100644
--- a/helper/ccnb-parser/visitors/ccnb-parser-depth-first-visitor.h
+++ b/helper/ccnb-parser/visitors/ccnb-parser-depth-first-visitor.h
@@ -27,7 +27,7 @@
 namespace CcnbParser {
 
 /**
- * \ingrou ccnx-ccnb
+ * \ingroup ccnx-ccnb
  * \brief Depth-first visitor that takes boot::any as argument and returns boost::any value
  */
 class DepthFirstVisitor : public Visitor
diff --git a/helper/ccnb-parser/visitors/ccnb-parser-no-argu-depth-first-visitor.h b/helper/ccnb-parser/visitors/ccnb-parser-no-argu-depth-first-visitor.h
index 1990d87..7d3841d 100644
--- a/helper/ccnb-parser/visitors/ccnb-parser-no-argu-depth-first-visitor.h
+++ b/helper/ccnb-parser/visitors/ccnb-parser-no-argu-depth-first-visitor.h
@@ -27,7 +27,7 @@
 namespace CcnbParser {
 
 /**
- * \ingrou ccnx-ccnb
+ * \ingroup ccnx-ccnb
  * \brief Depth-first visitor that takes no arguments and returns boost::any value
  */
 class NoArguDepthFirstVisitor : public NoArguVisitor
diff --git a/helper/ccnb-parser/visitors/ccnb-parser-void-depth-first-visitor.h b/helper/ccnb-parser/visitors/ccnb-parser-void-depth-first-visitor.h
index f2b78e3..35283d2 100644
--- a/helper/ccnb-parser/visitors/ccnb-parser-void-depth-first-visitor.h
+++ b/helper/ccnb-parser/visitors/ccnb-parser-void-depth-first-visitor.h
@@ -27,7 +27,7 @@
 namespace CcnbParser {
 
 /**
- * \ingrou ccnx-ccnb
+ * \ingroup ccnx-ccnb
  * \brief Depth-first visitor that takes one argument and returns nothing
  */
 class VoidDepthFirstVisitor : public VoidVisitor
diff --git a/helper/ccnb-parser/visitors/ccnb-parser-void-no-argu-depth-first-visitor.h b/helper/ccnb-parser/visitors/ccnb-parser-void-no-argu-depth-first-visitor.h
index 9237c2c..e796c7f 100644
--- a/helper/ccnb-parser/visitors/ccnb-parser-void-no-argu-depth-first-visitor.h
+++ b/helper/ccnb-parser/visitors/ccnb-parser-void-no-argu-depth-first-visitor.h
@@ -27,7 +27,7 @@
 namespace CcnbParser {
 
 /**
- * \ingrou ccnx-ccnb
+ * \ingroup ccnx-ccnb
  * \brief Depth-first visitor that takes no arguments and returns nothing
  */
 class VoidNoArguDepthFirstVisitor : public VoidNoArguVisitor