The search terms were identified through several trial and error attempts, replying on the prior experience of the authors and the keywords utilized in other sustainability and maritime logistics review papers. Through this process, a sophisticated keyword structure was designed combining a three-level search structure and a four-level search structure (see Table 1).Both three- and four-level structures use a similar set of exclusion keywords; however, the three-level structure aims to cover those articles that could not be captured by the primary four-level search. In the four-level structure, any combination of the first two levels can potentially return relevant articles; however, for some keywords, only certain combinations can result in meaningful results which are captured in the three-level keyword structure.