"Beltrami\u2013Klein model" . . . "Beltrami-Klein model" . "Beltrami–Klein model" . . . . "Beltrami\u2013Klein model" . . . "Models of hyperbolic geometry" . . "the Beltrami\u2013Klein model's relation to the Poincar\u00E9 disk model" . . . "the Beltrami\u2013Klein model's relation to the hyperboloid model" . "hyperbolic geometry" . .