diff --git a/SC3026.md b/SC3026.md
index bd08120..fd9dfd6 100644
--- a/SC3026.md
+++ b/SC3026.md
@@ -26,4 +26,5 @@ Or just rewrite it to be on the technically correct side.
 
 ### Related resources:
 
+* [2.13.1 Patterns Matching a Single Character](https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_13_01) in the Shell and Utilities (XCU) volume of POSIX.1-2017
 * Help by adding links to BashFAQ, StackOverflow, man pages, POSIX, etc!