“…In fact, many fundamental existence and uniqueness fixed-point results are established in metric spaces and further extended to their generalizations. Fixed-point problems were studied by Abbas-Rakočević-Iqbal [1,2], Ahmad-Arshad-Vetro [3], Di Bari-Vetro [10], Kadelburg-Radenović [12,13], La Rosa-Vetro [15], Samet [19], Vetro [24]. For other results in the setting of rectangular cone metric spaces see also Malhotra-Shukla-Sen [16] and Shukla [21].…”