http://www.aiaccess.net/French/Glossaires/GlosMod/f_gm_change_var.htm http://www.ilemaths.net/forum-sujet-61487.html http://books.google.fr/books?id=rprNjztQYPAC&pg=PA79&lpg=PA79&dq=theoreme+de+jirina&source=web&ots=5DTJqfu8KM&sig=W-rs2hyms7IZ1CgTaLho0VkLlT8&hl=fr&sa=X&oi=book_result&resnum=4&ct=result#PPA87,M1
