Reference for UNIX.

thesis.bib

@@ -1004,3 +1004,15 @@
   publisher = {{ACM}},
   year      = {1998}
 }
+
+# Unix
+@article{RitchieT74,
+  author    = {Dennis Ritchie and
+               Ken Thompson},
+  title     = {The {UNIX} Time-Sharing System},
+  journal   = {Commun. {ACM}},
+  volume    = {17},
+  number    = {7},
+  pages     = {365--375},
+  year      = {1974}
+}