FAO. (1991). World soil resources reports N.66: World soil resources. Rome: FAO.
Chicago Style aipamenaFAO. World Soil Resources Reports N.66: World Soil Resources. Rome: FAO, 1991.
MLA aipamenaFAO. World Soil Resources Reports N.66: World Soil Resources. Rome: FAO, 1991.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.