Lu, X. , Leino-Arjas, P. , Piha, K. , Aittomäki, A. , Saastamoinen, P. , Ossi Rahkonen, O. , Lahelma, E.. "On Methodologies for Analysing Sickness Absence Data: An Insight into a New Method". World Academy of Science, Engineering and Technology, Open Science Index 17, International Journal of Computer and Information Engineering (2008), 2(5), 1696 - 1701.