Lewine, Donald, POSIX Programmer's Guide: Writing Portable UNIX Programs, Sebastopol: O'Reilly & Associates, Inc., 1994

National Language Design Guide, Designing Enabled Products, Volume 1, 2nd ed., IBM reference SE09-8001-01

National Language Support Reference Manual, Volume 2, 2nd ed., IBM reference SE09-8001-02

X/Open Company, Ltd., X/Open Portability Guide, Volume 3 (Xsi Supplementary Definitions), Englewood Cliffs: Prentice Hall, 1989

Dr. International, Developing International Software, 2nd ed., Redmond: Microsoft Press, 2003