diff --git a/Distributed_Systems/site_reliability_engineering.md b/Distributed_Systems/site_reliability_engineering.md
index 03ca544..5ad2955 100644
--- a/Distributed_Systems/site_reliability_engineering.md
+++ b/Distributed_Systems/site_reliability_engineering.md
@@ -33,8 +33,10 @@
     - similar to *gRPC* or *BB BAS*
     - uses *protobufs*, check also *Apache Thrift*
 
+## Dev Environment
+[Mor12b] and [Pot16]
 
-## Reference
+>!Reference
 [Bur06]: http://research.google.com/archive/chubby-osdi06.pdf
 [Bur16]: https://research.google/pubs/pub44843.pdf
 [Cha06]: https://research.google/pubs/pub27898.pdf
@@ -43,5 +45,7 @@
 [Ghe03]: https://research.google.com/archive/gfs-sosp2003.pdf
 [Jai13]: http://conferences.sigcomm.org/sigcomm/2013/papers/sigcomm/p3.pdf
 [Kum15]: https://research.google/pubs/pub43838.pdf
+[Mor12b]: https://research.google/pubs/pub37755.pdf
+[Pot16]: https://www.youtube.com/watch?v=W71BTkUbdqE&feature=emb_logo
 [Sin15]: https://research.google.com/pubs/archive/43837.pdf
 [Ver15]: https://research.google.com/pubs/archive/43438.pdf