“…Notably, this sometimes leads to poorly justified classifications [62,63]. Knowledge-intensive services have also been defined according to different criteria, such as according to the depth of standardization of processes of knowledge generation and transformation [64], by focusing on the degree of innovation, interaction, and problem-solving of knowledge-generating activities [65,66] or by distinguishing knowledge-generating activities from research-intensive industries [67,68], financial services [69], or the cultural and creative sectors [70]. In contrast, Glückler et al (2008) [58] distinguish the service sector from the manufacturing sector by describing the economic branches E and G to O (The economic branches include E-electricity, gas, and water supply; G-wholesale and retail trade, repair of motor vehicles, motorcycles, and personal and household goods; H-hotels and restaurants; I-transport, storage, and communication; J-financial intermediation; K-real estate, renting, and business activities; L-public administration and defense, compulsory social security; M-education; N-health and social work; and O-other community, social, and personal service activ-ities [71].)…”