Brown, L. R. (1999). Vital Sings 1999: The trends that are shaping our future. New York: W. W. Norton & company.
Παραπομπή Chicago StyleBrown, Lester R. Vital Sings 1999: The Trends That Are Shaping Our Future. New York: W. W. Norton & company, 1999.
Παραπομπή MLABrown, Lester R. Vital Sings 1999: The Trends That Are Shaping Our Future. New York: W. W. Norton & company, 1999.
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