diff --git a/README.md b/README.md
index a007984..5ff2125 100644
--- a/README.md
+++ b/README.md
@@ -120,5 +120,6 @@ TODO
 [TNote]: https://github.com/tasdikrahman/tnote
 [DNote]: https://github.com/dnote
 [tmpfs]: https://wiki.archlinux.org/index.php/Tmpfs
+[shared_memory]: http://en.wikipedia.org/wiki/Shared_memory
 
-[^wpdtmpfs]: Recent 2.6 Linux kernel builds have started to offer /dev/shm as shared memory in the form of a ramdisk, more specifically as a world-writable directory that is stored in memory with a defined limit in /etc/default/tmpfs.  /dev/shm support is completely optional within the kernel config file. 
+[^wpdtmpfs]: [From Wikipedia][shared_memory] Recent 2.6 Linux kernel builds have started to offer /dev/shm as shared memory in the form of a ramdisk, more specifically as a world-writable directory that is stored in memory with a defined limit in /etc/default/tmpfs.  /dev/shm support is completely optional within the kernel config file.