code: public String[] getSources()
  	{
  		String source = tags != null ? tags.get("source") : null;
  		return source != null ? source.split("(\\s)?;(\\s)?") : null;
  	}
docs: A shortcut to getTags().get("source").split(";")
  @return the source of the data entered. Common values include "bing", "survey", "local
  knowledge", "common knowledge", "extrapolation", "photograph" (and more). null if
  none supplied.