Discussing quantum aspects of higher-derivative 3-D gravity in the first-order formalism J. A. Helayël-Neto, L. M. de Moraes and V. J. Vasquez Eur. Phys. J. C, 67 1-2 (2010) 311-319 Published online: 30 March 2010 DOI: 10.1140/epjc/s10052-010-1297-3