diff --git a/latex/commun.bib b/latex/commun.bib
index e69de29..2292959 100644
--- a/latex/commun.bib
+++ b/latex/commun.bib
@@ -0,0 +1,8 @@
+@ARTICLE{Tarjan72depthfirst,
+    author = {Robert Tarjan},
+    title = {Depth first search and linear graph algorithms},
+    journal = {SIAM JOURNAL ON COMPUTING},
+    year = {1972},
+    volume = {1},
+    number = {2}
+}