diff --git a/fractional/notes/frontier-map.url b/fractional/notes/frontier-map.url
new file mode 100644
index 0000000..9c74fc2
--- /dev/null
+++ b/fractional/notes/frontier-map.url
@@ -0,0 +1 @@
+http://www.jongware.com/galaxy1.html
diff --git a/fractional/notes/texture-mapping.url b/fractional/notes/texture-mapping.url
new file mode 100644
index 0000000..b838d2d
--- /dev/null
+++ b/fractional/notes/texture-mapping.url
@@ -0,0 +1,4 @@
+https://en.wikipedia.org/wiki/Texture_mapping
+http://www.gamers.org/dEngine/quake/papers/checker_texmap.html
+https://www.cs.uic.edu/~jbell/CourseNotes/ComputerGraphics/TextureMapping.html
+http://www.decew.net/OSS/References/chapter_2_texture_mapping.pdf