Andrew Gibson Matthew Gamble Katy Wolstencroft Tom Oinn Carole A. Goble Khalid Belhajjame Paolo Missier The data playground: An intuitive workflow specification environment. 453-459 2009 25 Future Generation Comp. Syst. 4 http://dx.doi.org/10.1016/j.future.2008.09.009 db/journals/fgcs/fgcs25.html#GibsonGWOGBM09