@article{articleb262329e,
title   = {Dual operators and phase structure of the z (4) - symmetric scalar field theory in 2+1 dimensions},
author = {Aragao de Carvalho, C A and Marino, E C and Marques, G C and Castro, M G},
year = {1988},
doi = {10.1103/physrevd.38.533},
journal   = {Physical Review D}
}