@inproceedings{1986-jahnichen ,note={URL: {\tt http://grosskurth.ca/\allowbreak bib/\allowbreak entries.html\#\allowbreak 1986/\allowbreak jahnichen}} ,author={Stefan J\"ahnichen and Fatima Ali Hussain and Matthias Weber} ,crossref={1986-conradi-book} ,title={{Program development by transformation and refinement}} ,year={1986} }