Peeter Laud Tarmo Uustalu Varmo Vene Type systems equivalent to data-flow analyses for imperative languages. 292-310 2006 364 Theor. Comput. Sci. 3 http://dx.doi.org/10.1016/j.tcs.2006.08.013 db/journals/tcs/tcs364.html#LaudUV06