“…Only one paper was published as a technical report and, hence, definitely non-refereed. [33], [34], [35], [36], [37], [27], [40], [30], [41], [31], [43], [32], [44] Empirical study without intervention 11 [18], [22], [24], [26], [15], [29], [19], [42], [20], [17], [21] Empirical study with intervention 5 [23], [38], [39], [25], [28] Opinion/philosophical paper 4 [13], [14], [2], [16] We also classified the included article in different types. We show the results in Tab.…”