1. Barton, G. J. TIBS 19, 554–555 (1994).
2. Schatz, B. R. & Hardin, J. B. Science 265, 895–901 (1994).
3. Schwartz, R. L. & Wall, L. in Programming Perl (O'Reilly & Associates, Sebastopolo, California 1992).
4. Ousterhout, J. in Tcl and the Tk Toolkit (Addison-Wesley, New York, 1994).
5. Peitsch, M. C., Stampf, D. R., Wells, T. N. C. & Sussman, J. L. TIBS 20, 82–84 (1995).