Small, C. and Douglas, P. and Johnson, R.G. and King, Peter J.H. and Martin, G.N., eds. (1997) Advances in databases, 15th British national conference on databases: BNCOD 15. Lecture Notes in Computer Science 1271. Springer.

King, P.J.H. and Johnson, R.G. (1974) Comments on the algorithms of Verhelst for the conversion of limited-entry decision tables to flowcharts. Communications of the ACM 17 (1), pp. 43-45. ISSN 0001-0782.