Source: http://www.ests.um5.ac.ma/cours/Dipl%C3%B4me%20Universitaire%20de%20Technologie/G%C3%A9nie%20Industriel%20et%20Maintenance/Semestre%2002/Analyse%20financi%C3%A8re/TD%20et%20exercices_Analyse%20financi%C3%A8re.pdf