“…We recall that on the one hand, it is of interest to establish the structure of the potential candidates for projections and, on the other hand, one should investigate whether the families of projections are unique or not. The studies on these matters were developed from various perspectives (see Aulbach and Kalkbrenner [1], Aulbach, Minh and Zabreiko [2], Barreira, Dragičević and Valls [5], Battelli, Franca and Palmer [9], Chow and Yi [19], Chow and Leiva [20,21], Dragičević, Sasu and Sasu [26], Kloeden and Rasmussen [34], Megan, Sasu and Sasu [36][37][38], Minh, Räbiger and Schnaubelt [41], Minh and Huy [42], Palmer [44,45], P ötzsche [51], Pliss and Sell [50], Sacker and Sell [55], Sasu [56], Sasu, Babut ¸ia and Sasu [63], Sasu and Sasu [57][58][59][60][61][62][64][65][66][67][68], Zhou, Lu and Zhang [72], Zhou and Zhang [73,75]). We stress that depending on the method, sometimes it is important to establish the structure of the (initial) stable subspace(s) (see Sasu [56], Sasu and Sasu [57,62,65], Sasu, Babut ¸ia and Sasu [63]), in some cases it is necessary to study the projections uniqueness (see Battelli, Franca and Palmer…”