التعريف: Organic matter in soil which has reached a point of stability, where it will break down no further and might, if conditions do not change, remain essentially as it is for centuries, or millennia.
التعريف: Museum für Naturkunde Berlin (Zoological Collections) (ZMB). Berlin, Germany. URL for main institutional website: http://www.naturkundemuseum-berlin.de Formerly Zoologisches Museum der Humboldt-Universität zu Berlin
