“…Several articles describe that the internal drivers are purchasing managers' intention [49], commitment to sustainability [59,89,90], internal environment orientation [90], alignment with corporate strategy [91,92], way of working with suppliers [59,91], and top management support [90]. The external drivers found include pressure from external stakeholders and environment e.g., customers [93], national culture [94], society [92,95], and regulatory [92]. Regarding the barriers of GS practices for sustainability, Wycherley (1999) [59] proposes commercial advantage and increased costs are two barriers in working with suppliers to improve the overall environmental impact.…”