1. J.-E. Roos, B. Sturmfels, A toric ring with irrational Poincaré–Betti series, C.R. Acad. Sci. Paris. Sér. I 326 (1998) 141–146.11There are two minor misprints in this paper:(i) On p. 145, line 1 you should add the words “dividing by” after “2.1, by”.(ii) On p. 145, line 18 replace “t2=0 and m3=tm2” by “b2=0 and m3=bm2”.
2. G. Scheja, Bettizahlen lokaler Ringe, Math. Ann. 155, 155–172.