“…Articles with a qualitative methodological approach were 40: individual interviews [18,20,24,27,30,33,35,40,48,52,54,57,58,61,75,80,86,88,89,95,101], focus groups [25,41,62,71,73] and participating observations [26,56,96]; furthermore, 5 studies [21,22,29,62,99] used both in-depth interviews and focus groups and 3 studies [56,76,92,103] both semi-structured interviews and participating observation. Finally, in 2 articles [21,86] a case study method was utilised.…”