. "Manganese nodule" . "Manganese_nodule" . . . . . . "Polymetallic Nodule" . "Mn nodules" . "manganese micro-nodules" . "manganese" . . "manganese nodules" . "Polymetallic nodules" . "manganese nodule" . . . . . "Manganese nodule" . "manganese-iron nodules" . "polymetallic nodule" . . . . "Manganese crusts" . "Manganese Nodules" . "nodules" . "polymetallic nodules" .