diff --git a/docs/source/api.rst b/docs/source/api.rst
index 10b0fa3..b157716 100644
--- a/docs/source/api.rst
+++ b/docs/source/api.rst
@@ -51,3 +51,4 @@ Follow the :doc:`build` documentation for this
    sphere
    curve
    bezier
+   version
diff --git a/docs/source/util.rst b/docs/source/util.rst
index 846934f..ad6f429 100644
--- a/docs/source/util.rst
+++ b/docs/source/util.rst
@@ -146,7 +146,7 @@ Functions documentation
       | *[in]*  **b**   b
 
     Returns:
-       true if a and b equals
+       true if a and b are equal
 
 .. c:function:: float glm_percent(float from, float to, float current)
 
@@ -158,7 +158,7 @@ Functions documentation
       | *[in]*  **current**   value between from and to values
 
     Returns:
-       clamped normalized percent (0-100 in 0-1)
+       percentage of current value
 
 .. c:function:: float glm_percentc(float from, float to, float current)
 
@@ -171,3 +171,11 @@ Functions documentation
 
     Returns:
        clamped normalized percent (0-100 in 0-1)
+
+.. c:function:: void glm_swapf(float *a, float *b) 
+
+    swap two float values
+
+    Parameters:
+      | *[in]*  **a**      float 1
+      | *[in]*  **b**      float 2
diff --git a/docs/source/version.rst b/docs/source/version.rst
new file mode 100644
index 0000000..01defa7
--- /dev/null
+++ b/docs/source/version.rst
@@ -0,0 +1,15 @@
+.. default-domain:: C
+
+version
+================================================================================
+
+Header: cglm/version.h
+
+**cglm** uses semantic versioning (http://semver.org) which is MAJOR.MINOR.PATCH 
+
+**CGLM_VERSION_MAJOR** is major number of the version.
+**CGLM_VERSION_MINOR** is minor number of the version.
+**CGLM_VERSION_PATCH** is path  number of the version.
+
+every release increases these numbers. You can check existing version by 
+including cglm/version.h