.SH References .LP .IP [1] K. L. Thompson and D. M. Ritchie, .ul The .ul .UC UNIX .ul Programmer's Manual, Bell Laboratories, 1978. .IP [2] B. W. Kernighan and D. M. Ritchie, .ul The C Programming Language, Prentice-Hall, Inc., 1978. .IP [3] B. W. Kernighan, .UC UNIX \& `` for Beginners \(em Second Edition.'' Bell Laboratories, 1978.