References

  1. "Unix Review" magazine, March, 1991, page 24, "A 4GL Language".
  2. "UNIX Relational Database Management", R. Manis, E. Schaffer, R. Jorgensen, 1988, Prentice Hall.
  3. "Programming PERL", L. Wall, R. Schwartz, 1991, O'Reilly & Associates.