Celebratio Mathematica

B. L. Feĭ­gin and D. B. Fuchs: “Verma mod­ules over the Vi­ra­s­oro al­gebra,” pp. 230–​245 in To­po­logy: Gen­er­al and al­geb­ra­ic to­po­logy, and ap­plic­a­tions (Len­in­grad, 23–27 Au­gust 1982). Edi­ted by L. D. Fad­deev and A. A. Mal’tsev. Lec­ture Notes in Math­em­at­ics 1060. Spring­er (Ber­lin), 1984. MR 770243 Zbl 0549.​17010 incollection