“…Many of these equations have already been studied in earlier papers on related topics. Among them, the equations with a weakly singular kernel in the network studies [10,21], in the non-linear Fredholm form [4,31], in the COVID-19 researches [29], in the non-linear Volterra-Fredholm form [28,32], in the non-linear Volterra form [16,17,30], in the linear Fredholm form [2,19,27], and others.…”