Source: http://www.ac-clermont.fr/fileadmin/user_upload/Actions_Educative/numerique-educatif/pedagogie/TRAAM/CoSciences/2016-2017/Formation_IFD_Co-sciences/Le_Puy-en-Velay/Travaux/Seance_2/Coll%C3%A8ge_SVT/SVT_seance_2_prof_compo_biologiques_Mars.pdf