private Document GET(String callName, String callPrefix, AlchemyAPI_Params params)
    throws IOException, SAXException,
           ParserConfigurationException, XPathExpressionException
	{
	    StringBuilder uri = new StringBuilder();
	    uri.append(_requestUri).append(callPrefix).append('/').append(callName)
	       .append('?').append("apikey=").append(this._apiKey);
	    uri.append(params.getParameterString());
	
	    URL url = new URL(uri.toString());
	    HttpURLConnection handle = (HttpURLConnection) url.openConnection();
	    handle.setDoOutput(true);
	
	    return doRequest(handle, params.getOutputMode());
	}