private String readSection(Document document, String firstLine, BufferedReader reader, HasSubSection parent) throws IOException {
		int currentlvl = getLvl(firstLine);
		Section section = new SectionImp(new TitleImp(firstLine.substring(currentlvl)), parent);
		String line;
		while((line = reader.readLine())!=null && !line.startsWith("*")) {
			section.getTextIntro().addLine(new LineImp(document.getTextIntro(), line));
		}
		
		while(line!= null && this.getLvl(line) > currentlvl) {
			line = this.readSection(document, line, reader, section);
		}
		
		parent.addSubSection(section);
		
		return line;
	}