Semantics, Analytics, Visualization 3rd International Workshop, SAVE-SD 2017, Perth, Australia, April 3, 2017, and 4th International Workshop, SAVE-SD 2018, Lyon, France, April 24, 2018, Revised Selected Papers - González-Beltrán, Alejandra; González-Beltrán, Alejandra; Osborne, Francesco; Osborne, Francesco; Peroni, Silvio; Peroni, Silvio; Vahdati, Sahar; Vahdati, Sahar (Springer International Publishing : Imprint: Springer, 2018)