Question: Street vendors might sell their goods in official places as well as where?
Answer: Street vendors play their trade from stalls in the tianguis as well as at non-officially controlled concentrations around metro stations and hospitals; at plazas comerciales, where vendors of a certain "theme" (e.g. stationery) are housed; originally these were organized to accommodate vendors formerly selling on the street; or simply from improvised stalls on a city sidewalk.
Is the question answered in a satisfactory fashion?
yes