private List<List<String>> importData(){
		List<List<String>> artistData = new ArrayList<List<String>>();
		
		// Find all .artistcleaned.
		StringBuilder sb = new StringBuilder();
		List<String> dataFiles = new ArrayList<String>();
		File[] files = new File("data").listFiles();
		for (File file : files) {
		    if (file.isFile()) {
		    	String fileName = file.getName();
		    	String artistID = fileName.substring(0,fileName.lastIndexOf("."));
		    	String fileEnd = fileName.substring(fileName.lastIndexOf(".") + 1, fileName.length());
		    	if(fileEnd.equals("artistcleaned")) {
		    		sb.append(artistID + "\n");
		    		dataFiles.add(fileName);
		    	}
		    }
		}
		
		try(PrintWriter pw = new PrintWriter("data/document_order.txt")) {
			pw.print(sb);
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		}
		
		//Read all files
		for(String fileName : dataFiles) {
			ArrayList<String> artistBio = new ArrayList<String>();
			artistData.add(artistBio);
			try(BufferedReader br = new BufferedReader(new FileReader("data/" + fileName))) {
		        String line = br.readLine();
		        while (line != null) {
		        	artistBio.add(line);
		            line = br.readLine();
		        }
		    } catch(IOException e) {
		    	e.printStackTrace();
		    }
		}
		
		return artistData;
	}