The GNU 64-bit PL8 compiler: Toward an open standard environment for firmware development. - Wolfgang Gellerich; Torsten Hendel; Rudolf Land; Helge Lehmann; Michael Mueller; Peter H. Oden; Hartmut Penner (IBM J. Res. Dev., 2004)

Open-standard development environment for IBM System z9 host firmware. - Christine Axnix; Torsten Hendel; Michael Mueller; Angel Nuñez Mencias; Hartmut Penner; Stefan Usenbinz (IBM J. Res. Dev., 2007)