TY JOUR TI Combining two sheets of quasi-rotation surfaces KW rotation KW quasi-rotation KW shaping KW curve axis KW circle KW ellipse KW Dupin's cyclide KW cyclic surfaces KW axis of rotation KW high-order surface KW high-order curve JO Journal of Natural Sciences Research AU Kudziev, K.V. PY 2021 IS 6 PB INFRA-M Academic Publishing LLC.