diff --git a/s390x.md b/s390x.md
index 9449265..42cf957 100644
--- a/s390x.md
+++ b/s390x.md
@@ -9,6 +9,7 @@
 - https://wiki.qemu.org/Documentation/Platforms/S390X
 - https://arstechnica.com/information-technology/2023/07/the-ibm-mainframe-how-it-runs-and-why-it-survives/
 - https://sdl-hercules-390.github.io/html/
+- Big-endian s390x https://community.ibm.com/community/user/ibmz-and-linuxone/blogs/javier-perez1/2021/01/19/endianness-guidance-for-open-source-projects
 
 ***