diff --git a/references/2017_arch_pie.pdf b/references/2017_arch_pie.pdf
new file mode 100644
index 0000000..f3e1e74
Binary files /dev/null and b/references/2017_arch_pie.pdf differ
diff --git a/work/bibliography.bib b/work/bibliography.bib
index 56978fa..88e9f16 100644
--- a/work/bibliography.bib
+++ b/work/bibliography.bib
@@ -81,6 +81,15 @@ year = {2001}
   number={4},
 }
 
+@techreport{Gcc2003,
+  author = {{Wagle}, Perry and {Cowan}, Crispin},
+  institution = {{Immunix, Inc.}},
+  title = {{StackGuard: Simple Stack Smash Protection for GCC}},
+  url = {ftp://gcc.gnu.org/pub/gcc/summit/2003/Stackguard.pdf},
+  year = {2003},
+  urlDate = {2019-12-15}
+}
+
 @article{Counter2012,
   author = {{{Younan}, Yves and {Joosen}, Wouter and {Piessens}, Frank}},
   title = {{Runtime countermeasures for code injection attacks against C and C++
@@ -108,6 +117,23 @@ year={2007}
   url={https://www.cvedetails.com/vulnerability-list/year-2018/opov-1/overflow.html}
 }
 
+@online{ArchPie2017,
+  url =
+  {https://git.archlinux.org/svntogit/packages.git/commit/trunk?h=packages/gcc&id=5936710c764016ce306f9cb975056e5b7605a65b},
+  urlDate = {2019-12-15},
+  year = {2017},
+  author = {{Bartłomiej Piotrowski}},
+  title = {{7.1.1-4: enable SSP and PIE by default}}
+}
+
+@online{Tiobe2019,
+  author = {{TIOBE}},
+  title = {{TIOBE Index for December 2019}},
+  urlDate = {2019-12-15},
+  year = {2019},
+  url = {https://www.tiobe.com/tiobe-index/}
+}
+
 @online{FBSDaslr,
   url = {https://svnweb.freebsd.org/base?view=revision\&revision=r343964},
   year = {2019},