Juha Puustjärvi Henry Tirri Jari Veijalainen Reusability and Modularity in Transactional Workflows. 101-120 1997 22 Inf. Syst. 2/3 db/journals/is/is22.html#PuustjarviTV97 http://dx.doi.org/10.1016/S0306-4379(97)00007-0