diff --git a/README.md b/README.md
index 9e92eb0..2c4d491 100644
--- a/README.md
+++ b/README.md
@@ -104,3 +104,11 @@ mkdir build && cd build
 cmake -GNinja -DP2T_BUILD_TESTBED=ON
 cmake --build .
 ```
+
+References
+==========
+
+- Domiter V. and Zalik B. (2008) Sweep‐line algorithm for constrained Delaunay triangulation
+- FlipScan by library author Thomas Åhlén
+
+![FlipScan](doc/FlipScan.png)
diff --git a/doc/FlipScan.png b/doc/FlipScan.png
new file mode 100644
index 0000000..2571886
Binary files /dev/null and b/doc/FlipScan.png differ
diff --git a/poly2tri/sweep/sweep.h b/poly2tri/sweep/sweep.h
index ccf4ef7..895b0e8 100644
--- a/poly2tri/sweep/sweep.h
+++ b/poly2tri/sweep/sweep.h
@@ -33,7 +33,7 @@
  * Zalik, B.(2008)'Sweep-line algorithm for constrained Delaunay triangulation',
  * International Journal of Geographical Information Science
  *
- * "FlipScan" Constrained Edge Algorithm invented by Thomas ?hl?n, thahlen@gmail.com
+ * "FlipScan" Constrained Edge Algorithm invented by Thomas �hl�n, thahlen@gmail.com
  */
 
 #ifndef SWEEP_H