Celebratio Mathematica

I. Ka­plansky: “The split­ting of mod­ules over in­teg­ral do­mains,” Arch. Math. (Basel) 13 (1962), pp. 341–​343. Ded­ic­ated to Re­in­hold Baer on his 60th birth­day. MR 0144939 Zbl 0108.​26302

W. C. Jagy and I. Ka­plansky: “In­def­in­ite bin­ary quad­rat­ic forms with Markov ra­tio ex­ceed­ing 9,” pp. 305–​316 in Spe­cial is­sue in hon­or of Re­in­hold Baer (1902–1979), published as Illinois J. Math. 47 : 1–​2 (2003). MR 2031324 Zbl 1084.​11036