Celebratio Mathematica

P. F. Baum: “On the co­homo­logy of ho­mo­gen­eous spaces,” To­po­logy 7 : 1 (January 1968), pp. 15–​38. MR 219085 Zbl 0158.​42002 article

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