Celebratio Mathematica

P. Baum and R. Bott: “Sin­gu­lar­it­ies of holo­morph­ic fo­li­ations,” J. Diff. Geom. 7 : 3–​4 (1972), pp. 279–​342. To S. S. Chern and D. C. Spen­cer on their 60th birth­days. MR 377923 Zbl 0268.​57011 article

P. Baum: “Riemann–Roch the­or­em for sin­gu­lar vari­et­ies,” pp. 3–​16 in Dif­fer­en­tial geo­metry (Stan­ford, CA, 30 Ju­ly–17 Au­gust 1973), part 2. Edi­ted by S. S. Chern and R. Os­ser­man. Pro­ceed­ings of Sym­po­sia in Pure Math­em­at­ics 27. Amer­ic­an Math­em­at­ic­al So­ci­ety (Provid­ence, RI), 1975. MR 389907 Zbl 0344.​32021 incollection