Celebratio Mathematica

P. Baum, A. Connes, and N. Hig­son: “Clas­si­fy­ing space for prop­er ac­tions and $K$-the­ory of group $C^{\ast }$-al­geb­ras,” pp. 241–​291 in $C^{\ast }$-al­geb­ras: 1943–1993 (San Ant­o­nio, TX, 13–14 Janu­ary 1993). Edi­ted by R. S. Dor­an. Con­tem­por­ary Math­em­at­ics 167. Amer­ic­an Math­em­at­ic­al So­ci­ety (Provid­ence, RI), 1994. MR 1292018 Zbl 0830.​46061 incollection