%T Perimeter Approximation of Convex Discs in the Hyperbolic Plane and on the Sphere %V 66 %P 1190-1201 %R MTMT:31957366 10.1007/s00454-021-00291-7 %N 3 %L publicatio24974 %D 2021 %I szte %J DISCRETE AND COMPUTATIONAL GEOMETRY %A Fodor Ferenc