“…The above publications of non-homogeneous semi-Markov and Markov renewal processes for credit risk was followed by quite a lot of literature by the same and other authors in credit risk and related subjects. For example, from recent years, see Huang [13], D' Amico et al [14,15], D' Amico [16], Magni et al [17], Wu et al [18,19], Puneet et al [20], De Blasis [21]. In D' Amico et al [22], bivariate semi-Markov processes are introduced for the pricing of Credit Default Swaps (CDS).…”