Source: https://www.researchgate.net/profile/Meddour-Belkacem/publication/327499957_Theorie_des_mecanismes_Cours_Exercices_6_eme_Semestre_Licence_LMD_Constructions_Mecaniques/links/5b9250e692851c78c4f43838/Theorie-des-mecanismes-Cours-Exercices-6-eme-Semestre-Licence-LMD-Constructions-Mecaniques.pdf