anchor.diff:  
   + Response 200 (application/json)
       + Attributes (Source)
  +
  +### View a source with statements [GET /sources/{id}{?include}]
  +
  ++ Parameters
  +    + id: 1 (required, string) - ID of the source; TODO shouldn't we use URIs?
  +    + include: statements (string, optional) - include statements from this URI
  +
  ++ Response 200 (application/json)
  +    + Attributes (Source)
  +        + included (array[Statement Object])
   
   ## Sources list [/sources]
   
  
positive.code: They can include news articles or govermental websites, 
  but also youtube video and other online sources.
  
  ## Source [/sources/{id}]
  
  + Parameters
      + id: 1 (required, string) - ID of the source; TODO shouldn't we use URIs?
  
negative.code: + type: source (string, fixed)
  + attributes
      + uri: http://www.agerpres.ro/politica/2016/07/10/dragnea-de-cand-e-gabriela-firea-primar-nu-s-a-taiat-niciun-pom-pe-kiseleff-21-41-07 (string)
  + relationships
      + statements
          + links
              + self: http://factual.ro/api/sources/1/relationships/statements (string)
              + related: http://factual.ro/api/sources/1/statements (string)
          + data
              + type: statement (string, fixed)
              + id: 1 (string)
  