Zheying Zhang Mike Arvela Eleni Berki Matias Muhonen Jyrki Nummenmaa Timo Poranen Towards Lightweight Requirements Documentation. 882-889 2010 3 JSEA 9 http://dx.doi.org/10.4236/jsea.2010.39103 db/journals/jsea/jsea3.html#ZhangABMNP10