diff --git a/relativity/Special_Relativistic_Visualization_by_Local_Ray_Tracing.pdf b/relativity/Special_Relativistic_Visualization_by_Local_Ray_Tracing.pdf
new file mode 100644
index 0000000..3fce47b
--- /dev/null
+++ b/relativity/Special_Relativistic_Visualization_by_Local_Ray_Tracing.pdf
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:c3b76aabcb884e20b0325bf7e6f18dd253524435e1ca548b095c08107f35dfd2
+size 6446732
diff --git a/relativity/an-immersive-virtual-environment-for-special-relativity.pdf b/relativity/an-immersive-virtual-environment-for-special-relativity.pdf
new file mode 100644
index 0000000..4357ee7
--- /dev/null
+++ b/relativity/an-immersive-virtual-environment-for-special-relativity.pdf
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:3323ae022aa0e21f44d52bb35ec2e4637b638228ecc501cc5dbb788da4d363d2
+size 307656
diff --git a/relativity/gyoto.pdf b/relativity/gyoto.pdf
new file mode 100644
index 0000000..b64b063
--- /dev/null
+++ b/relativity/gyoto.pdf
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:1459636bfb7824cb183cdb42b3e900e6c64b1b1c439a76358dcbd37eb503cdd5
+size 746118