“…for suitable real constants µ 1 , µ 2 , H, and α ∈ (0, 1). Many papers have been devoted to equations of this type (see for example the classical references [4,7] or the more recent ones [1,2,3,5,6,8,9,10,12,13,15,16]). Let us briefly discuss the previous results that are more relevant to our presentation.…”