1. Proc. Sixth Berkely Symp., Math. Statist. Prob;Belyayev Yu. K.,1972
2. Sojourns and Extremes of Stationary Processes
3. Blake I. F.andLindsey W. C.(1971).IEEE Trans. Inf. Theory 295–315. (A useful introduction to the engineering literature on level‐crossing problems up to 1971. The bibliography has 133 references.)