Analysis of information sources in references of the Wikipedia article "Hàng hóa thiết yếu" in Vietnamese language version.
[...] as the consumer gets more income, he consumes more of both goods but proportionally more of one good (the luxury good) than of the other (the necessary good).
[...] as the consumer gets more income, he consumes more of both goods but proportionally more of one good (the luxury good) than of the other (the necessary good).
