Bai, Y., Z. Abouguendia, and R.E. Redmann (2001), Relationship between plant species diversity and grassland condition, Journal of Range Management, 54: 177-183. ###>Bai, Y., Z. Abouguendia et R.E. Redmann (2001), Relationship between plant species diversity and grassland condition, Journal of Range Management, 54: 177-183.