Author not established. País. Date not established. EHREA archive: /library/documents/doc-7cdfd21e2145c39343d0dbef/
[1] País. Original source: http://www.ehrea.org/dem.pdf. Preserved original: /library/originals/011e4b73a2a7de81d7fb773fdda685222f4687477e73bc0b5ed480eb2d8b9e84.pdf. SHA-256: 011e4b73a2a7de81d7fb773fdda685222f4687477e73bc0b5ed480eb2d8b9e84