diff --git a/trees/dt/dt-0005.tree b/trees/dt/dt-0005.tree
index 4bc922b..a589638 100644
--- a/trees/dt/dt-0005.tree
+++ b/trees/dt/dt-0005.tree
@@ -1,4 +1,5 @@
 \import{dt-macros}
+\parent{dt-001Y}
 \title{Semantics and recursion}
 \taxon{Lecture}
 \author{liamoc}
diff --git a/trees/dt/dt-001Z.tree b/trees/dt/dt-001Z.tree
index 60dabfd..82780c5 100644
--- a/trees/dt/dt-001Z.tree
+++ b/trees/dt/dt-001Z.tree
@@ -1,4 +1,5 @@
 \import{dt-macros}
+\parent{dt-001Y}
 \import{table-macros}
 \taxon{Lecture}
 \title{Constructions on [cpos](dt-001D) and PCF}
diff --git a/trees/dt/dt-004Z.tree b/trees/dt/dt-004Z.tree
index 24f248e..c03136b 100644
--- a/trees/dt/dt-004Z.tree
+++ b/trees/dt/dt-004Z.tree
@@ -1,4 +1,5 @@
 \taxon{Lecture}
+\parent{dt-001Y}
 \author{liamoc}
 \title{Recursively defined domains and #{\lambda}-calculus}
 \p{This lecture is based on material from [[haskellhutt]], [[jlongley]], [[danascott]], [[jstoy]], [[cgunter]], and [[gwinskel]].}
diff --git a/trees/dt/dt-005V.tree b/trees/dt/dt-005V.tree
index d4b3b20..bd4a962 100644
--- a/trees/dt/dt-005V.tree
+++ b/trees/dt/dt-005V.tree
@@ -1,5 +1,6 @@
 \import{dt-macros}
 \taxon{Lecture}
+\parent{dt-001Y}
 \author{liamoc}
 \title{Monadic semantics, Scott domains and nondeterminism}
 \p{This lecture is based on material from [[cgunter]], [[gwinskel]], [[haskellhutt]], [[kaie]], [[dexterkozen]], [[andrewmyers]], [[jlongley]], [[danascott]], and [[jstoy]].}