Quantized o (1,2) / o (2)*z2 sigma model has no continuum limit in 4 dimensions. 2. Lattice simulation - Lyra, Jorge Lacerda de; Dewitt, B; Foong, S K; Gallivan, T E; Harrington, R; Kapulkin, A; Myers, E; Polchinski, J (Physical Review D, 1992)