“…Table 7 provides an overview of the category unit of analysis found in the articles included in the review. First of all, it is interesting to notice that only 61 out 207 papers are focused on specific types of purchases (29%); defense purchasing is the most addressed, especially as an example of procurement practices at the central government level (e.g., Buchanan & Klingner, 2007;San Miguel et al, 2008;Roberts, 2010); then, with a similar number of papers, there are professional services (e.g., Schiele, 2009), construction (e.g., Patil & Molenaar, 2011) and health purchasing (e.g., Verhage et al, 2002). Surprisingly, a spectrum of categories remained comparatively understudied: no article considers environment and social care purchasing, while ICT and indirect purchases (e.g., MRO), education purchasing and transport are rarely addressed (e.g., Deis et al, 2004;Sieverding, 2008;Leviäkangas, 2013).…”