“…The exponential functionals of a Lévy processes have become a key object in stochastic modelling, for instance one founds these r.v. in the following areas: random algorithms [30], composition structures [27,26], generalized Ornstein-Uhlenbeck processes [43], finance [65], financial time series [36], population dynamics [23] and [45], random media [60], risk theory [22] and [25], self-similar fragmentation theory [5] and [9], self-similar Markov processes theory [12,16,37,40,19,49], self-similar branching processes [41] and [51], random networks [34], telecommunications [30], quantum mechanics [20] and many others, see e.g. [12].…”