1. Jones C B. Systematic Software Development Using VDM. Prentice-Hall, Second edition, 1990.
2. Havelund K. and Haxthausen A. RSL Reference Manual. Technical Report RAISE/CRI/DOC/2/V1, Computer Resources International, 1990.
3. Harry P. History Specifications. HP Labs Internal Report, 1991.
4. Stallman R. The extensible, customizable, self documenting, display editor. In Interactive Programming Environments. McGraw-Hill, 1984.
5. Rush T., Harry P., Ferguson T., and Oliver H. Case studies in HP-SL. Technical Report HPL-90-137, Hewlett-Packard Laboratories, Bristol, 1990.