diff --git a/Modelica/Mechanics/MultiBody/Frames/Quaternions/from_T.mo b/Modelica/Mechanics/MultiBody/Frames/Quaternions/from_T.mo
index a79b8f095a..8a73e77eae 100644
--- a/Modelica/Mechanics/MultiBody/Frames/Quaternions/from_T.mo
+++ b/Modelica/Mechanics/MultiBody/Frames/Quaternions/from_T.mo
@@ -14,7 +14,7 @@ protected
 algorithm
   /*
    This is an optimized version of the quaternion conversion based on
-   this paper: https://d3cw3dd2w32x2b.cloudfront.net/wp-content/uploads/2015/01/matrix-to-quat.pdf
+   this paper: modelica://Modelica/Resources/Documentation/Mechanics/matrix-to-quat.pdf
 */
   if T[3, 3] < 0 then
     if T[1, 1] > T[2, 2] then
@@ -74,7 +74,7 @@ package.
 <ul>
   <li>January 2021 by Jakub Tobolar<br>
        reimplemented for more efficient and numerically stable algorithm according to
-       <a href=\"https://d3cw3dd2w32x2b.cloudfront.net/wp-content/uploads/2015/01/matrix-to-quat.pdf\">https://d3cw3dd2w32x2b.cloudfront.net/wp-content/uploads/2015/01/matrix-to-quat.pdf</a>.
+       <a href=\"modelica://Modelica/Resources/Documentation/Mechanics/matrix-to-quat.pdf\">matrix-to-quat.pdf</a>.
        It compares only one particular diagonal element with another to
        select one of the four code parts. Then, the selected code delivers
        four components which are close to the desired quaternion,
diff --git a/Modelica/Resources/Documentation/Mechanics/matrix-to-quat.pdf b/Modelica/Resources/Documentation/Mechanics/matrix-to-quat.pdf
new file mode 100644
index 0000000000..00d2de61d5
Binary files /dev/null and b/Modelica/Resources/Documentation/Mechanics/matrix-to-quat.pdf differ