diff --git a/docs/linux/git.md b/docs/linux/git.md
index bccc60d..96aca33 100644
--- a/docs/linux/git.md
+++ b/docs/linux/git.md
@@ -25,4 +25,22 @@ then
 	GIT_COMMITTER_NAME=$NEW_NAME 
 fi' -- --all
 
+```
+
+
+## git subtree 
+
+
+### add a subtree
+
+```
+git subtree add --prefix my-subdirectory http://mysite.com/my_other_project.git master --squash
+```
+
+
+### update a  subtree 
+
+```
+git subtree pull --prefix my-subdirectory http://mysite.com/my_other_project.git master --squash
+
 ```
\ No newline at end of file