public static Collection<Document> parseLibraryTFIDF() throws FileNotFoundException {
		Set<Document> result = new HashSet<Document>();
		Map<String, Integer> docFrequency = new HashMap<String, Integer>();
		
		for (String filename : LIBRARY){
			Set<String> seenWords = new HashSet<String>();
			String filePath = "data/" + filename;
			Scanner fileScan = new Scanner(new File(filePath));
			fileScan.useDelimiter("[^\\w']+"); // do a bit of cleaning to disregard punctuation
			while(fileScan.hasNext()){
				String word = fileScan.next().toLowerCase();
				if(!seenWords.contains(word)){
					seenWords.add(word);
					if(!docFrequency.containsKey(word)){
						docFrequency.put(word, 0);
					}
					docFrequency.put(word, docFrequency.get(word) + 1);
				}
			}
			
		}
		for (String filename : LIBRARY){
			String filePath = "data/" + filename;
			Scanner fileScan = new Scanner(new File(filePath));
			result.add(new Document(filename, fileScan, docFrequency, LIBRARY.length));
		}
		return result;
	}