@article{DAN_1961_137_1_a2,
     author = {A. D. Venttsel'},
     title = {Non-negative additive functionals of {Markov} processes},
     journal = {Doklady Akademii Nauk},
     pages = {17--20},
     publisher = {mathdoc},
     volume = {137},
     number = {1},
     year = {1961},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1961_137_1_a2/}
}