Supplementary materials: Orientations of patents for eight selected enterprises

Detail orientations of Ri: R1-e-liquid; R2-e-cigarette cases; R3-batteries and charging devices; R4-switches; R5-atomizer and atomization methods; R6-heater parts; R7-materials of e-cigarette; R8-appearance of e-cigarette; R9-smoke flow; R10-oil transportation, storage and supply devices; R11-control systems; R12-others