@article{GDZPPN002180073,
title = {The Semigroup Property for the Birth and Death Process.},
journal = {Journal f\"ur die reine und angewandte Mathematik},
volume = {212},
year = {1963},
pages = {80-103},
zbl = {0124.08605},
url = {http://dml.mathdoc.fr/item/GDZPPN002180073}
}
Kemperman, J.H.B. The Semigroup Property for the Birth and Death Process.. Journal für die reine und angewandte Mathematik, Tome 212 (1963) pp. 80-103. http://gdmltest.u-ga.fr/item/GDZPPN002180073/