diff --git a/sd/8/3/b.txt b/sd/8/3/b.txt
index f9a0259..2ba7a5f 100644
--- a/sd/8/3/b.txt
+++ b/sd/8/3/b.txt
@@ -1,4 +1,4 @@
-# SD8 Workflow Management Systems principles
+# SD8.3 Workflow Management Systems principles
 
 Workflow Management Systems are tools to enable reproducible data analysis, especially if many data analyis processing steps are involved.
 
diff --git a/use/2/b.txt b/use/2/b.txt
index b4a0b9b..a18e91b 100644
--- a/use/2/b.txt
+++ b/use/2/b.txt
@@ -13,4 +13,4 @@ Moreover, individual solutions can often be found in a specific system.
 ## Subskills
 
 * [[skill-tree:use:2:1:b]]
-* [[skill-tree:use:1:2:b]]
+* [[skill-tree:use:2:2:b]]
diff --git a/use/6/4/b.txt b/use/6/4/b.txt
index bad924f..d62ea92 100644
--- a/use/6/4/b.txt
+++ b/use/6/4/b.txt
@@ -1,9 +1,9 @@
 # USE6.4 Running workflows
 
-## Requirements:
+## Requirements
 
 * [[skill-tree:use:5:1:3:b]]
-* [[skill-tree:use:4:2:b]]
+* [[skill-tree:use:4:b]]
 * optionally: [[skill-tree:sd:3:1:b]]
 
 ## Learning Objectivs