Celebratio Mathematica

R. Bott: “On the shape of a curve,” Adv. Math. 16 : 2 (May 1975), pp. 144–​159. Ded­ic­ated to Stan Ulam. Also pub­lished in Sur­veys in ap­plied math­em­at­ics: Es­says ded­ic­ated to Stan­islaw Ulam (1976). MR 0383392 Zbl 0308.​55011 article

R. Bott: “On the shape of a curve,” pp. 23–​38 in Sur­veys in ap­plied math­em­at­ics: Es­says ded­ic­ated to Stan­islaw Ulam (Los Alam­os, NM, 12–18 June 1974). Edi­ted by N. Poin­caré, S. Or­sz­ag, and G.-C. Rota. Aca­dem­ic Press (New York), 1976. Also pub­lished in Adv. Math. 16:2 (1975). MR 0645193 incollection