diff --git a/004/codex-004.tex b/004/codex-004.tex
index bc80b93..3c72333 100644
--- a/004/codex-004.tex
+++ b/004/codex-004.tex
@@ -135,6 +135,16 @@ Bush II decided to tank the economy for ordinary people so that rich people coul
 
 \chapter{Math in \LaTeX{} with \texttt{align} and \texttt{array}}
 
+\chapter{Searching your Bash History}
+
+https://www.cyberciti.biz/faq/linux-unix-shell-history-search-command/
+
+https://www.digitalocean.com/community/tutorials/how-to-use-bash-history-commands-and-expansions-on-a-linux-vps
+
+https://superuser.com/questions/7414/how-can-i-search-the-bash-history-and-rerun-a-command
+
+https://www.gnu.org/savannah-checkouts/gnu/bash/manual/bash.html\#Bindable-Readline-Commands
+
 \chapter{What's to Like About Linux}
 
 \chapter{More about those folders in \texttt{root}}