Bazo-Alvarez, Juan Carlos, et al. “The Circumplex Three-Dimensional (3D) Model: On the Non-Curvilinear FACES-III Measurements”. Revista Peruana De Medicina Experimental Y Salud Pública, vol. 34, no. 1, Mar. 2017, pp. 152-3, https://doi.org/10.17843/rpmesp.2017.341.2782.