EDIT

		DescriptionElementSource source = textData.getSources().iterator().next();

		Reference<?> ref = source.getCitation();

		assertNotNull("Citation should not be null", ref);

		assertEquals("Source author should be 'Meyer et. al.'", "Meyer et. al.",ref.getAuthorship().getTitleCache());

		assertEquals("Publication title should be 'My first book'", "My first book", ref.getTitle());

		assertEquals("Publication year should be '1987'", "1987", ref.getYear());

		source = textData.getSources().iterator().next();

		ref = source.getCitation();

		assertNotNull("Citation should not be null", ref);

		assertEquals("Source author should be 'Theys, A.'", "Theys, A.",ref.getAuthorship().getTitleCache());

		assertEquals("Publication title should be 'The ultimate book'", "The ultimate book", ref.getTitle());

		assertEquals("Publication year should be '2011'", "2011", ref.getYear());