- Recovery rate of Niobium Ore in World and by Country in 2001Jan 15, 2002
- Recovery rate of Niobium Ore in the World in 2001Jan 15, 2002
- Recovery rate of Niobium Ore in the World in 2000Jan 15, 2001
- Recovery rate of Niobium Ore in World and by Country in 2000Jan 15, 2001
- Recovery rate of Niobium Ore in World and by Country in 1999Jan 15, 2000
- Recovery rate of Niobium Ore in the World in 1999Jan 15, 2000
- Recovery rate of Niobium Ore in the World in 1998Jan 15, 1999
- Recovery rate of Niobium Ore in World and by Country in 1998Jan 15, 1999
