Celebratio Mathematica

D. L. Burk­hold­er: “On the num­ber of es­capes of a mar­tin­gale and its geo­met­ric­al sig­ni­fic­ance,” pp. 159–​178 in Al­most every­where con­ver­gence: Pro­ceed­ings of the in­ter­na­tion­al con­fer­ence on al­most every­where con­ver­gence in prob­ab­il­ity and er­god­ic the­ory (Colum­bus, OH, 11–14 June 1988). Edi­ted by G. A. Edgar and L. Suche­ston. Aca­dem­ic Press (Bo­ston, MA), 1989. MR 1035244 Zbl 0685.​60049 incollection