@article{FORUM_1989__1_3_141621,
     author = {Hiroyuki Okura},
     title = {Recurrence {Criteria} for {Skew} {Products} of {Symmetric} {Markov} {Processes.}},
     journal = {Forum mathematicum},
     pages = {331--358},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {1989},
     zbl = {0686.60079},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1989__1_3_141621/}
}