Source: https://www.researchgate.net/profile/Mickael_Coustaty/publication/267961188_Ontologies_et_relations_spatiales_dans_une_image_application_aux_images_de_lettrines/links/54b792400cf2bd04be33a551/Ontologies-et-relations-spatiales-dans-une-image-application-aux-images-de-lettrines.pdf