diff --git a/Documentation/TableofContents.md b/Documentation/TableofContents.md
index 922da5e..64c61f4 100644
--- a/Documentation/TableofContents.md
+++ b/Documentation/TableofContents.md
@@ -19,7 +19,7 @@
 <br>[3.1 CONCEPT](StandardizedVocabularies/CONCEPT.md)
 <br>[3.2 VOCABULARY](StandardizedVocabularies/VOCABULARY.md)
 <br>[3.3 DOMAIN](StandardizedVocabularies/DOMAIN.md)
-<br>[3.4 CONCEPT_CLASS]StandardizedVocabularies/CONCEPT_CLASS.md)
+<br>[3.4 CONCEPT_CLASS](StandardizedVocabularies/CONCEPT_CLASS.md)
 <br>3.5 CONCEPT_RELATIONSHIP
 <br>3.6 RELATIONSHIP
 <br>3.7 CONCEPT_SYNONYM