diff --git a/submodules/externals/libxsd b/submodules/externals/libxsd
new file mode 160000
index 000000000..97dfa5b7a
--- /dev/null
+++ b/submodules/externals/libxsd
@@ -0,0 +1 @@
+Subproject commit 97dfa5b7af486a2730aa66ef4b2b04259c9ab21b
diff --git a/submodules/externals/soci b/submodules/externals/soci
new file mode 160000
index 000000000..908c7eb8f
--- /dev/null
+++ b/submodules/externals/soci
@@ -0,0 +1 @@
+Subproject commit 908c7eb8f421601e6eb7b77e1131a35bcbe374fa
diff --git a/submodules/externals/xerces-c b/submodules/externals/xerces-c
new file mode 160000
index 000000000..9c15b9917
--- /dev/null
+++ b/submodules/externals/xerces-c
@@ -0,0 +1 @@
+Subproject commit 9c15b9917507c584eadace89636b91af27b59b9c