diff --git a/diagrams/example.puml b/diagrams/example.puml
index db2840b..da6b0de 100644
--- a/diagrams/example.puml
+++ b/diagrams/example.puml
@@ -13,7 +13,7 @@
         }
 
     object "<u>10.1016/j.ejor.2020.09.020: Journal Article</u>" as article09020 #ddeedd {
-            DOI = "10.1016/j.ejor.2020.09.020" ^^ DOI_Type
+            DOI = "10.1016/j.ejor.2020.09.020" ^^ DOI
             title = "The responsibility of social media in times of
             \t societal and political manipulation"@en
             publicationDate = 2021-06-16 ^^ Date
@@ -23,8 +23,8 @@
             number = "3"
             authors = [ X ] ^^ List<Agent>
             authorships = [ Authorship 1 ] ^^ List<Authorship>
-            accessRights = Open Access: Open Access COAR v.1.0 Accessibility
-            \t Specification ^^ Textual Document Accessibility Specification
+            accessRights = Open Access ^^ Open_Access_COAR_Accessibility_Specification_v_1_0
+            \t Specification ^^ Textual_Document_Accessibility_Specification
             source = EJOR ^^ Journal
     }
 
diff --git a/diagrams/module.puml b/diagrams/module.puml
index dd63275..22b79da 100644
--- a/diagrams/module.puml
+++ b/diagrams/module.puml
@@ -18,10 +18,10 @@
 
     !startsub Journal
         class "Journal" #ddeedd {
-            DOI : DOI_Type
+            DOI : DOI
             title : Multilingual_String
-            ISSN : ISSN_Type
-            eISSN : ISSN_Type
+            ISSN : ISSN
+            eISSN : ISSN
             acronym : Multilingual_String
             startDate : Date
             endDate : Date
@@ -36,8 +36,8 @@
     !endsub
 
     class "Monograph" #ddeedd {
-        ISBN : ISBN_Type
-        eISBN : ISBN_Type
+        ISBN : ISBN
+        eISBN : ISBN
     }
     class "Editorship" #ddeedd {
         leadingEditorFlag : Boolean
diff --git a/entities/Journal.md b/entities/Journal.md
index d7eaf22..d9932a1 100644
--- a/entities/Journal.md
+++ b/entities/Journal.md
@@ -7,7 +7,7 @@ A [journal article](../entities/Journal_Article.md) should contain information a
 
 ## Attributes
 
-DOI: [DOI_Type](https://github.com/EuroCRIS/CERIF-Core/blob/main/datatypes/DOI.md) 
+DOI: [DOI](https://github.com/EuroCRIS/CERIF-Core/blob/main/datatypes/DOI.md) 
 
 title: [Multilingual String](https://github.com/EuroCRIS/CERIF-Core/blob/main/datatypes/Multilingual_String.md)