diff --git a/pages/common/slimrb.md b/pages/common/slimrb.md
index 975cc975be..47c4833333 100644
--- a/pages/common/slimrb.md
+++ b/pages/common/slimrb.md
@@ -1,6 +1,7 @@
 # slimrb
 
 > Convert Slim files to HTML.
+> More information: <https://rdoc.info/gems/slim/frames#slim-command-slimrb>.
 
 - Convert a Slim file to HTML:
 
diff --git a/pages/common/sn.md b/pages/common/sn.md
index ca98de1c37..c20adfaccc 100644
--- a/pages/common/sn.md
+++ b/pages/common/sn.md
@@ -1,6 +1,7 @@
 # sn
 
 > Mono StrongName utility for signing and verifying IL assemblies.
+> More information: <https://manned.org/sn>.
 
 - Generate a new StrongNaming key:
 
diff --git a/pages/common/socat.md b/pages/common/socat.md
index 83f82aacff..e039859f41 100644
--- a/pages/common/socat.md
+++ b/pages/common/socat.md
@@ -1,6 +1,7 @@
 # socat
 
 > Multipurpose relay (SOcket CAT).
+> More information: <http://www.dest-unreach.org/socat/>.
 
 - Listen to a port, wait for an incoming connection and transfer data to STDIO:
 
diff --git a/pages/common/swig.md b/pages/common/swig.md
index 8ba7d920d9..adb429738d 100644
--- a/pages/common/swig.md
+++ b/pages/common/swig.md
@@ -2,6 +2,7 @@
 
 > Generate bindings between C / C++ code and various high level languages such as JavaScript, Python, C#, and more.
 > It uses special .i or .swg files to generate the bindings (C/C++ with SWIG directives, then outputs a C/C++ file that contains all the wrapper code needed to build an extension module.
+> More information: <http://www.swig.org>.
 
 - Generate a binding between C++ and Python: