@article{10_4064_cm_5_2_223_230,
     author = {K. Urbanik},
     title = {Remarks on invariant functions in {Markov} processes},
     journal = {Colloquium Mathematicum},
     pages = {223--230},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1957},
     doi = {10.4064/cm-5-2-223-230},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/cm-5-2-223-230/}
}