1. Ross SM (2011) Introduction to probability models, 10th edn. Academic, San Diego
2. Feller W (1971) An introduction to probability theory and its applications, vol II. Wiley, New York
3. Trivedi KS (2002) Probability and statistics with reliability, queuing and computer science applications, 2nd edn. Wiley, Hoboken
4. Anjum B, Perros HG (2011) Adding percentiles of erlangian distributions. IEEE Commun Lett 15(3):346–348
5. Jasiulewicz H, Kordecki W (2003) Convolutions of Erlang and of Pascal distributions with applications to reliability. Demonstratio Math 36(1):231–238