“…Forty-three articles which discussed the concept of the RfE and/or that collected or used RfE data were included in this review. Of these, 14 elaborated on the RfE concept, 11,[38][39][40][41][43][44][45][46][47][48][49][50][51] 29 used ICPC as a classification, 9,10,13,14,18,23,25,27,28,30,[33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] and 7 originated from or were closely related to the Transition Project, with which the two authors are closely associated. 13,23,27,41,44,50,…”