This is a custom Google search which should find relevant data on the web. Try searching vietnam gdp, obesity or miguel cabrera. Use the "image tab" in the results for possible graphs or other visualizations.
You also want to try Quandl or Zanran
Journal articles often include statistical data. They will also include a reference to the data source. This widget will search Summon for most of Schaffer Library's journal articles that include data sets.