Ralph Mietzner Dimka Karastoyanova Frank Leymann Business Grid: Combining Web Services and the Grid. 136-151 2009 2 T. Petri Nets and Other Models of Concurrency http://dx.doi.org/10.1007/978-3-642-00899-3_8 journals/topnoc/2009-2 db/journals/topnoc/topnoc2.html#MietznerKL09