diff --git a/book/design/Beton/Beton.md b/book/design/Beton/Beton.md
index 2e8c3b1..2900956 100644
--- a/book/design/Beton/Beton.md
+++ b/book/design/Beton/Beton.md
@@ -1,4 +1,4 @@
-# Beton
+# Concrete
 
 This chapter contains the following sections:
 
diff --git a/book/design/Hout/Hout.md b/book/design/Hout/Hout.md
index 115af01..087d4a2 100644
--- a/book/design/Hout/Hout.md
+++ b/book/design/Hout/Hout.md
@@ -1,4 +1,4 @@
-# Hout
+# Wood
 
 This chapter contains the following sections:
 
diff --git a/book/design/Staal/Staal.md b/book/design/Staal/Staal.md
index ff91338..bed5c16 100644
--- a/book/design/Staal/Staal.md
+++ b/book/design/Staal/Staal.md
@@ -1,4 +1,4 @@
-# Staal
+# Steel
 
 This chapter contains the following sections: