@article{BrandtBrandt2012, author = {Manfred Brandt and Andreas Brandt}, title = {Additive functionals with application to sojourn times in infinite-server and processor sharing systems}, journal = {Queueing Systems}, volume = {70}, number = {4}, pages = {369 -- 409}, doi = {10.1007/s11134-012-9282-1}, year = {2012}, }